Exhibit 7.1

(1 of 2)

PETRÓLEOS MEXICANOS, SUBSIDIARY ENTITIES AND SUBSIDIARY COMPANIES

Computation of ratio of earnings to fixed charges

(in thousands of
pesos)(1)



|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|---------------------------------------------------------------------------- |  | ----------- | - |  | ------------ | - |  | ----------- | - |  | ----------- | - |  | ----------- | -
|                                                                             |  | 2009        |   |  | 2008         |   |  | 2007        |   |  | 2006        |   |  | 2005        |  
|Mexican Financial Reporting Standards                                        |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|Fixed
Charges(2):                                                            |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|Interest capitalized in fixed assets                                         |  | 3,813,747   |   |  | 1,057,440    |   |  | 5,350,849   |   |  | 6,996,305   |   |  | 5,540,983   |  
|Interest expense                                                             |  | 78,300,095  |   |  | 73,883,856   |   |  | 57,847,569  |   |  | 46,099,472  |   |  | 57,146,232  |  
|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|Total interest cost                                                          |  | 82,113,842  |   |  | 74,941,296   |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|Total Fixed Charges                                                          |  | 82,113,842  |   |  | 74,941,296   |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|Net income                                                                   |  | (94,662,018 | ) |  | (112,076,444 | ) |  | (18,307,569 | ) |  | 46,953,205  |   |  | (82,357,983 | )
|Hydrocarbons Income Tax (IRP)                                                |  | 2,502,651   |   |  | 1,582,910    |   |  | 6,030,367   |   |  | 4,914,859   |   |  | 2,135,245   |  
|Income Tax and Others                                                        |  | 6,219,098   |   |  | 8,885,312    |   |  | 3,226,241   |   |  | 4,605,044   |   |  | 3,981,678   |  
|Cumulative effect of adoption of new accounting standards                    |  |            |   |  |             |   |  |            |   |  |            |   |  | (1,905,868  | )
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  | 1,291,487   |   |  | 1,965,213    |   |  | (5,545,054  | ) |  | (10,073,577 | ) |  | (8,658,665  | )
|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|                                                                             |  |             |   |  |             
|Pretax income from continuing operations before income from equity investees |  | (84,648,782 | ) |  | (99,643,009  | ) |  | (14,596,015 | ) |  | 46,399,531  |   |  | (86,805,593 | )
|Fixed
Charges(2):                                                            |  | 82,113,842  |   |  | 74,941,296   |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|Amortization of interest capitalized                                         |  | 152,550     |   |  | 42,298       |   |  | 214,034     |   |  | 279,852     |   |  | 221,639     |  
|Distribution of income from investments in shares                            |  |            |   |  | 2,923,216    |   |  | 3,558,680   |   |  | 5,876,453   |   |  | 5,486,425   |  
|Interest capitalized in fixed assets                                         |  | (3,813,747  | ) |  | (1,057,440   | ) |  | (5,350,849  | ) |  | (6,996,305  | ) |  | (5,540,983  | )
|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|Earnings                                                                     |  | (6,196,137  | ) |  | (22,793,639  | ) |  | 47,024,268  |   |  | 98,655,308  |   |  | (23,951,297 | )
|                                                                             |  |             |   |  |              |   |  |             |   |  |             |   |  |             |  
|                                                                             |  |             |   |  |             
|Amount by which fixed charges exceed earnings                                |  | 88,309,979  |   |  | 97,734,935   |   |  | 16,174,150  |   |  |             |   |  | 86,638,512  |  
|Ratio of earnings to fixed charges                                           |  |             |   |  |              |   |  |             |   |  | 1.8581      |   |  |             |  



|(1) | Figures for 2005 and 2006 are stated in constant pesos as of December 31, 2007. Figures for 2008 and 2009 are stated in constant pesos as of December 31,
2009.
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------

|(2) | These figures do not include rental expense.
|--- | --------------------------------------------



---

Exhibit 7.1

(2 of 2)

PETRÓLEOS MEXICANOS, SUBSIDIARY ENTITIES AND SUBSIDIARY COMPANIES

Computation of ratio of earnings to fixed charges

(in thousands of
pesos)(1)



|                                                                             |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|---------------------------------------------------------------------------- |  | ----------- | - |  | ----------- | - |  | ----------- | - |  | ----------- | - |  | ----------- | -
|                                                                             |  | 2009        |   |  | 2008        |   |  | 2007        |   |  | 2006        |   |  | 2005        |  
|U.S. GAAP                                                                    |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|Fixed
Charges(2):                                                            |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|Interest capitalized in fixed assets                                         |  | 3,813,747   |   |  | 559,607     |   |  | 7,797,815   |   |  | 8,659,013   |   |  | 6,321,963   |  
|Interest expense                                                             |  | 78,300,095  |   |  | 74,381,689  |   |  | 55,400,603  |   |  | 44,436,764  |   |  | 56,365,252  |  
|                                                                             |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|Total interest cost                                                          |  | 82,113,842  |   |  | 74,941,296  |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|Total Fixed Charges                                                          |  | 82,113,842  |   |  | 74,941,296  |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|                                                                             |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|Net income                                                                   |  | (52,572,107 | ) |  | (67,765,607 | ) |  | (32,642,076 | ) |  | 56,722,446  |   |  | (79,791,073 | )
|Hydrocarbons Income Tax (IRP)                                                |  | 2,456,637   |   |  | 1,570,288   |   |  | 5,967,879   |   |  | 4,840,082   |   |  | 2,577,913   |  
|Income Tax and Others                                                        |  | 6,219,098   |   |  | 8,885,312   |   |  | 3,226,241   |   |  | 4,605,044   |   |  | 3,981,678   |  
|Cumulative effect of adoption of new accounting standards                    |  |            |   |  |            |   |  |            |   |  |            |   |  | (1,905,868  | )
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  | 1,291,487   |   |  | (1,815,570  | ) |  | (5,791,312  | ) |  | (7,078,235  | ) |  | (7,828,486  | )
|Non-controlling interest                                                     |  | (160,285    | ) |  | (140,652    | ) |  | 6,089       |   |  | 54,789      |   |  | (1,159,233  | )
|Pretax income from continuing operations before income from equity investees |  | (42,765,170 | ) |  | (59,266,229 | ) |  | (29,233,179 | ) |  | 59,144,126  |   |  | (84,125,069 | )
|Fixed
Charges(2):                                                            |  | 82,113,842  |   |  | 74,941,296  |   |  | 63,198,418  |   |  | 53,095,777  |   |  | 62,687,215  |  
|Amortization of interest capitalized                                         |  | 152,550     |   |  | 22,384      |   |  | 311,913     |   |  | 346,361     |   |  | 252,879     |  
|Distribution of income from investments in shares                            |  |            |   |  | 2,923,216   |   |  | 3,558,680   |   |  | 5,876,453   |   |  | 5,486,425   |  
|Interest capitalized in fixed assets                                         |  | (3,813,747  | ) |  | (559,607    | ) |  | (7,797,815  | ) |  | (8,659,013  | ) |  | (6,321,963  | )
|                                                                             |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|Earnings                                                                     |  | 35,687,475  |   |  | 18,061,060  |   |  | 30,038,017  |   |  | 109,803,704 |   |  | (22,020,513 | )
|                                                                             |  |             |   |  |             |   |  |             |   |  |             |   |  |             |  
|                                                                             |  |             |   |  |            
|Amount by which fixed charges exceed earnings                                |  | 46,426,367  |   |  | 56,880,236  |   |  | 33,160,401  |   |  |             |   |  | 84,707,728  |  
|Ratio of earnings to fixed charges                                           |  |             |   |  |             |   |  |             |   |  | 2.0680      |   |  |             |  



|(1) | Figures for 2005 and 2006 are stated in constant pesos as of December 31, 2007. Figures for 2008 and 2009 are stated in constant pesos as of December 31,
2009.
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------

|(2) | These figures do not include rental expense.
|--- | --------------------------------------------