THIRD ADDENDUM TO DISTRIBUTOR FRANCHISE AGREEMENT

Exhibit 10.12

THIRD ADDENDUM TO DISTRIBUTOR FRANCHISE AGREEMENT

This Third Addendum to Distributor Franchise Agreement is entered into by and between CITGO Petroleum Corporation (“CITGO”) and SSP Partners (“SSP”) on September 6, 1999.

WHEREAS, CITGO and SSP have entered into a Distributor Franchise Agreement as amended on January 15, 1996 and as amended on June 23, 1998 (collectively the “DFA”);

WHEREAS, SSP has received offers from other suppliers to purchase motor fuels on a formula related basis, and therefore, has requested that CITGO sell branded gasoline on a formula related basis; and

WHEREAS, CITGO has agreed to sell CITGO branded motor fuels to SSP in accordance with the terms as provided herein; provided that no marketing programs, other than branding and credit card are provided to SSP for company operated units; and provided further, that SSP extends the term of the DFA to August 1, 2006.

NOW THEREFORE in consideration of the premises and covenants contained herein, it is agreed as follows:

1. The term of the DFA is extended to August 1, 2006.

2. The purchase price for motor fuels sold by CITGO to SSP and lifted on and after August 2, 1999, for CITGO branded stations (and certain unbranded stations that are conflicting with other CITGO branded stations) that are operated by SSP (collectively, the “Stores”) shall be equal to (i) the [***] for the applicable grade of motor fuel as of the date of lifting, (ii) less [***] per gallon, (iii) plus CITGO’s product delivery costs (PDC) for the applicable terminal, (iv) plus a portion of each Store’s gasoline profits and merchandise profits as described to subparagraphs 2.3 and 2.4 below and (v) plus any applicable taxes. The purchase price will not be reduced by any prompt payment discount. The Stores are identified in the attached Exhibit A, which Exhibit will be amended from time to time as necessary.

2.1 Should Platts not be published on the date of lifting, the immediate preceding date upon which Platts is published shall be used to determine the purchase price.

2.2 This purchase price shall only be available for motor fuels delivered to the Stores.

2.3 As a part of the purchase price for motor fuels, SSP shall pay CITGO [***] of SSP’s gross margins from its sales of gasoline at the Stores. For purposes herein, gross margins from its sales of gasoline shall be the difference between SSP’s costs for the motor fuels, excluding the portion of the costs determined under the first sentence of this subparagraph 2.3 and under subparagraph 2.4, but, including applicable

taxes and transportation costs, and the price at which SSP sells the motor fuels at the Stores, and calculated in a manner consistent with SSP’s past accounting practices.

2.4 As a part of the purchase price for motor fuels, SSP shall pay CITGO [***] of SSP’s gross profit net from the sale of merchandise (excluding motor fuels) at the Stores. For purposes herein, gross profit net from the sale of merchandise shall mean the selling price of such merchandise less (i) the costs of such merchandise (reduced by vendor rebates) and (ii) the costs associated with unsaleable inventory, net inventory shrinkage, and net cash shortages, calculated in a manner consistent with SSP’s past accounting practices.

2.5 CITGO’s PDC shall be reviewed and adjusted annually to reflect CITGO’s actual costs for having the product available at the particular terminal, including exchange differential, without allocation of indirect costs such as corporate overhead, Listed on Exhibit B attached hereto is CITGO’s current PDC for each of the terminals, both primary and secondary, presently used to supply motor fuels to SSP. It is acknowledged that the PDC information is proprietary and confidential and SSP agrees not to disclose it to any third party.

2.6 SSP shall provide to CITGO on or before the 23rd day of each month, SSP’s monthly income statement for the immediate preceding month for the Stores in sufficient detail to calculate the portion of the purchase price set forth in subparagraphs 2.3 and 2.4. Furthermore, SSP shall furnish to CITGO on an annual basis an audited income statement. CITGO may, during normal business hours and upon reasonable notice and at its own expense, inspect and audit the books and records of SSP for the Stores.

2.7 SSP shall pay CITGO’s invoices based on rack price by EFT in accordance with CITGO’s payment terms (the “Invoice Price”). However, each month the parties agree to reconcile the difference between the purchase price, as determined under paragraph 2, and the Invoice Price. If the purchase price is less than the Invoice Price, CITGO shall credit SSP the difference. If the purchase price is more than the Invoice Price, SSP shall pay CITGO the difference.

3. For each Store that SSP operates that is branded with CITGO on August 2, 1999, or subsequently becomes a CITGO branded outlet operated by SSP, SSP will receive a CITGO branding allowance of up to [***] for branding materials, including cladding, signage, quad band and round corners. SSP will pay for all installation and incremental cost of backlit letters. CITGO also agrees to provide brand maintenance materials up to an aggregate amount for all Stores of [***] per year.

2

4. CITGO’s credit card services and fees will be the same regardless if the motor fuels are priced under paragraph 2 of this Addendum or otherwise; provided that SSP will not be charged more than any other CITGO distributor except the 7-Eleven Company.

5. Except as otherwise provided under paragraphs 3 and 4 above, SSP shall not receive any benefits from any CITGO marketing program for the Stores as the pricing formula is being provided in lieu of other marketing programs, including but not limited to the Image Allowance Program (IAP). Dealer sites are not subject to this Addendum and shall remain eligible for all programs for which such sites qualify.

6. Within a sixty day period each year, thirty days before and 30 days after the anniversary of the effective date of this Addendum, either party may request in writing that the pricing provisions of this Addendum be renegotiated because of a material or significant change in (i) market conditions, (ii) SSP’s gasoline sales and gross margins, (iii) SSP’s merchandise sales and gross margins, (iv) Platt’s being recognized as a market indicator, (v) senior management changes at either SSP or CITGO or (vi) other conditions that affect either party’s economics under this Addendum. Upon a written request of renegotiation, both parties will attempt to negotiate a new purchase price for motor fuels. If the parties are unable to reach an agreement on the purchase price, either party may terminate the pricing provisions of paragraph 2 upon providing a minimum of ninety (90) days written notice prior to January 31 of the following year. In such event, the date of termination shall be January 31 of the year immediately following the year in which notice was given. The then current pricing provision shall remain in effect until termination. Upon termination of such pricing provision, this Third Addendum shall also terminate and the parties’ rights, duties and obligations with respect to the DFA, are as set forth in the DFA as amended and modified, including the January 15, 1996 and June 23, 1998 Addendums. SSP has certain termination rights under paragraph 1 of the January 15, 1996 Addendum and SSP may provide the 90 day termination notice of the DFA at the same time that it provides notice of termination of the pricing provisions and of this Third Addendum. Furthermore, should CITGO provide notice of termination of the pricing provisions of this Third Addendum, SSP may provide notice of termination of the DFA provided such notice is either provided (i) on or before 90 days prior to January 31 of the immediate following year or (ii) within thirty (30) days of receipt of CITGO’s notice of termination of the pricing provisions. It is acknowledged that if the volume of SSP’s branded gasoline purchases from CITGO for a Contract Year falls ten percent (10%) or more below the immediate preceding Contract Year’s volume, CITGO may request a renegotiation of the pricing provisions of this Addendum. For purpose of this Addendum, Contract Year shall mean August 2 to August 1 of the next year.

7. SSP will offer to brand with CITGO all new or acquired company operated stores in Texas, Oklahoma, Louisiana, Arkansas, and New Mexico, outside of Harris County, Texas, provided that, any stores acquired under contractual commitments would not be required to be branded with CITGO until expiration of the commitment. CITGO agrees to supply SSP’s current and future motor fuel requirements; provided that, CITGO will attempt, but is not required, to supply SSP’s additional motor fuel requirements in Shreveport, West Texas and New Mexico.

3

8. Except with respect to the 7-Eleven Company, CITGO shall not give a formula price for the purchase of motor fuels to any other CITGO branded marketer in any terminal area in which SSP lifts CITGO branded motor fuels, which formula price CITGO could reasonably expect to result in a lower motor fuels price than that being paid by SSP hereunder, unless such formula price is also offered to SSP for such terminal area. Furthermore, CITGO shall not give a Platt’s related formula price with a sharing of the marketer’s margin for the purchase of motor fuels to any CITGO branded marketer, applicable to a terminal area in which SSP lifts CITGO branded motor fuels, which formula price CITGO could reasonably expect to result in a lower motor fuels price than that being paid by SSP hereunder, unless such Platt’s related formula price with a sharing of marketer’s margins is also offered to SSP. Nothing herein is intended to inhibit CITGO from making any equity purchase from a third party or require CITGO to make any equity purchase offer to SSP. It is acknowledged that an equity purchase, in whole or part, is excluded from the terms of this paragraph 8.

9. SSP agrees not to debrand any CITGO branded Store that has a branding commitment period remaining under a CITGO Program until such commitment period has been satisfied, unless SSP pays the then unamortized portion of the IAP relating to the particular Store that is debranded. The parties acknowledge that SSP may, from time to time, brand new Stores and debrand existing Stores. Except as set forth in paragraph 7 of the January 15, 1998 Addendum, SSP agrees not to debrand any Store, without CITGO’s written consent, if SSP’s volume of branded gasoline purchased from CITGO for such current Contract Year would not at least equal [***] percent [***] of the immediate preceding Contract Year’s volume of branded gasoline purchased by SSP from CITGO.

10. All other terms of the DFA, as amended, not modified herein, shall remain in full force and effect.

IN WITNESS WHEREOF, this Addendum was executed on the date above written.

4

EXHIBIT A

STORE ADDRESS AND TELEPHONE LIST

5

6

7

EXHIBIT B

PDC for SSP

8

PDC for SSP

9

PDC for SSP

10