Exhibit 7.1

(1 of 2)

PETRÓLEOS MEXICANOS, SUBSIDIARY ENTITIES AND SUBSIDIARY
COMPANIES

Computation of ratio of earnings to fixed charges

(in thousands of Mexican pesos)(1)



|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|---------------------------------------------------------------------------- |  | ---- | ----------- | - | ---- |  | ----------- | ---- |  |  | ------------ | - |  | ---- | ----------- | - |  |  | ----------- | -
|                                                                             |  | 2010 |             |   | 2009 |  |             | 2008 |  |  | 2007         |   |  | 2006 |            
|Mexican FRS                                                                  |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Fixed Charges(2):                                                            |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Interest capitalized in fixed assets                                         |  |      | 2,295,178   |   |      |  | 3,813,747   |      |  |  | 1,057,440    |   |  |      | 5,350,849   |   |  |  | 6,996,305   |  
|Interest expense                                                             |  |      | 74,382,083  |   |      |  | 78,300,095  |      |  |  | 73,883,856   |   |  |      | 57,847,569  |   |  |  | 46,099,472  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Total interest cost                                                          |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296   |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|Total Fixed Charges                                                          |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296   |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Net income                                                                   |  |      | (47,462,608 | ) |      |  | (94,662,018 | )    |  |  | (112,076,444 | ) |  |      | (18,307,569 | ) |  |  | 46,953,205  |  
|Hydrocarbon Income Tax (IRP)                                                 |  |      | 2,459,557   |   |      |  | 2,502,651   |      |  |  | 1,582,910    |   |  |      | 6,030,367   |   |  |  | 4,914,859   |  
|Income Tax and Others                                                        |  |      | 1,724,806   |   |      |  | 6,219,098   |      |  |  | 8,885,312    |   |  |      | 3,226,241   |   |  |  | 4,605,044   |  
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  |      | (1,118,176  | ) |      |  | 1,291,487   |      |  |  | 1,965,213    |   |  |      | (5,545,054  | ) |  |  | (10,073,577 | )
|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Pretax income from continuing operations before income from equity investees |  |      | (44,396,421 | ) |      |  | (84,648,782 | )    |  |  | (99,643,009  | ) |  |      | (14,596,015 | ) |  |  | 46,399,531  |  
|Fixed Charges(2):                                                            |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296   |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|Amortization of interest capitalized                                         |  |      | 91,807      |   |      |  | 152,550     |      |  |  | 42,298       |   |  |      | 214,034     |   |  |  | 279,852     |  
|Distribution of income from investments in shares                            |  |      |            |   |      |  |            |      |  |  | 2,923,216    |   |  |      | 3,558,680   |   |  |  | 5,876,453   |  
|Interest capitalized in fixed assets                                         |  |      | (2,295,178  | ) |      |  | (3,813,747  | )    |  |  | (1,057,440   | ) |  |      | (5,350,849  | ) |  |  | (6,996,305  | )
|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Earnings                                                                     |  |      | 30,077,469  |   |      |  | (6,196,137  | )    |  |  | (22,793,639  | ) |  |      | 47,024,268  |   |  |  | 98,655,308  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |              |   |  |      |             |   |  |  |             |  
|Amount by which fixed charges exceed earnings                                |  |      | 46,599,792  |   |      |  | 88,309,979  |      |  |  | 97,734,935   |   |  |      | 16,174,150  |   |  |  |            |  
|Ratio of earnings to fixed charges                                           |  |      |            |   |      |  |            |      |  |  |             |   |  |      |            |   |  |  | 1.8581      |  



|(1) | Figures for 2006 have been restated to constant pesos as of December 31, 2007, by applying the inflation factor, as measured by the NCPI, from December 31, 2006 through
December 31, 2007. Figures for 2007 are stated in constant pesos as of December 31, 2007. Figures for 2008, 2009 and 2010 are stated in nominal pesos.
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(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 Mexican pesos)(1)



|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|---------------------------------------------------------------------------- |  | ---- | ----------- | - | ---- |  | ----------- | ---- |  |  | ----------- | - |  | ---- | ----------- | - |  |  | ----------- | -
|                                                                             |  | 2010 |             |   | 2009 |  |             | 2008 |  |  | 2007        |   |  | 2006 |            
|U.S. GAAP                                                                    |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Fixed Charges(2):                                                            |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Interest capitalized in fixed assets                                         |  |      | 2,295,178   |   |      |  | 3,813,747   |      |  |  | 559,607     |   |  |      | 7,797,815   |   |  |  | 8,659,013   |  
|Interest expense                                                             |  |      | 74,382,083  |   |      |  | 78,300,095  |      |  |  | 74,381,689  |   |  |      | 55,400,603  |   |  |  | 44,436,764  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Total interest cost                                                          |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296  |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|Total Fixed Charges                                                          |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296  |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Net income                                                                   |  |      | (17,442,291 | ) |      |  | (52,572,107 | )    |  |  | (67,765,607 | ) |  |      | (32,642,076 | ) |  |  | 56,722,446  |  
|Hydrocarbon Income Tax (IRP)                                                 |  |      | 2,417,760   |   |      |  | 2,456,637   |      |  |  | 1,570,288   |   |  |      | 5,967,879   |   |  |  | 4,840,082   |  
|Income Tax and Others                                                        |  |      | 1,724,806   |   |      |  | 6,219,098   |      |  |  | 8,885,312   |   |  |      | 3,226,241   |   |  |  | 4,605,044   |  
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  |      | (1,118,176  | ) |      |  | 1,291,487   |      |  |  | (1,815,570  | ) |  |      | (5,791,312  | ) |  |  | (7,078,235  | )
|Non-controlling interest                                                     |  |      | (217,437    | ) |      |  | (160,285    | )    |  |  | (140,652    | ) |  |      | 6,089       |   |  |  | 54,789      |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|                                                                             |  |      |             |   |     
|Pretax income from continuing operations before income from equity investees |  |      | (14,635,338 | ) |      |  | (42,765,170 | )    |  |  | (59,266,229 | ) |  |      | (29,233,179 | ) |  |  | 59,144,126  |  
|Fixed Charges(2):                                                            |  |      | 76,677,261  |   |      |  | 82,113,842  |      |  |  | 74,941,296  |   |  |      | 63,198,418  |   |  |  | 53,095,777  |  
|Amortization of interest capitalized                                         |  |      | 91,807      |   |      |  | 152,550     |      |  |  | 22,384      |   |  |      | 311,913     |   |  |  | 346,361     |  
|Distribution of income from investments in shares                            |  |      |            |   |      |  |            |      |  |  | 2,923,216   |   |  |      | 3,558,680   |   |  |  | 5,876,453   |  
|Interest capitalized in fixed assets                                         |  |      | (2,295,178  | ) |      |  | (3,813,747  | )    |  |  | (559,607    | ) |  |      | (7,797,815  | ) |  |  | (8,659,013  | )
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Earnings                                                                     |  |      | 59,838,552  |   |      |  | 35,687,475  |      |  |  | 18,061,060  |   |  |      | 30,038,017  |   |  |  | 109,803,704 |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|                                                                             |  |      |             |   |     
|Amount by which fixed charges exceed earnings                                |  |      | 16,838,709  |   |      |  | 46,426,367  |      |  |  | 56,880,236  |   |  |      | 33,160,401  |   |  |  |            |  
|Ratio of earnings to fixed charges                                           |  |      |            |   |      |  |            |      |  |  |            |   |  |      |            |   |  |  | 2.0680      |  



|(1) | Figures for 2006 have been restated to constant pesos as of December 31, 2007, by applying the inflation factor, as measured by the NCPI, from December 31, 2006 through
December 31, 2007. Figures for 2007 are stated in constant pesos as of December 31, 2007. Figures for 2008, 2009 and 2010 are stated in nominal pesos.
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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