Exhibit 7.1

(1 of 2)

PETROLEOS MEXICANOS SUBSIDIARY ENTITIES AND SUBSIDIARY
COMPANIES

Computation of ratio of earnings to fixed charges

(In Thousands of Mexican pesos)(1)



|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|---------------------------------------------------------------------------- |  | ---- | ----------- | - | ---- |  | ----------- | ---- |  |  | ----------- | - |  | ---- | ------------ | - |  |  | ----------- | -
|                                                                             |  | 2011 |             |   | 2010 |  |             | 2009 |  |  | 2008        |   |  | 2007 |             
|Mexican GAAP                                                                 |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Fixed Charges(2):                                                            |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Interest capitalized in fixed assets                                         |  |      | 4,292,351   |   |      |  | 2,295,178   |      |  |  | 3,813,747   |   |  |      | 1,057,440    |   |  |  | 5,350,849   |  
|Interest expense                                                             |  |      | 62,631,063  |   |      |  | 74,382,083  |      |  |  | 78,300,095  |   |  |      | 73,883,856   |   |  |  | 57,847,569  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Total interest cost                                                          |  |      | 66,923,414  |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296   |   |  |  | 63,198,418  |  
|Total Fixed Charges                                                          |  |      | 66,923,414  |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296   |   |  |  | 63,198,418  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Net income                                                                   |  |      | (91,483,321 | ) |      |  | (46,527,237 | )    |  |  | (94,369,846 | ) |  |      | (110,822,681 | ) |  |  | (18,307,569 | )
|Hydrocarbon Income Tax (IRP)                                                 |  |      | 708,469     |   |      |  | 2,459,557   |      |  |  | 2,502,651   |   |  |      | 1,582,910    |   |  |  | 6,030,367   |  
|Income Tax and Others                                                        |  |      | 3,969,740   |   |      |  | 1,938,451   |      |  |  | 6,219,098   |   |  |      | 8,885,312    |   |  |  | 3,226,241   |  
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  |      | 796,398     |   |      |  | (1,540,688  | )    |  |  | 767,228     |   |  |      | 1,965,213    |   |  |  | (5,545,054  | )
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Pretax income from continuing operations before income from equity investees |  |      | (86,008,714 | ) |      |  | (43,669,917 | )    |  |  | (84,880,869 | ) |  |      | (98,389,246  | ) |  |  | (14,596,015 | )
|Fixed Charges(2):                                                            |  |      | 66,923,414  |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296   |   |  |  | 63,198,418  |  
|Amortization of interest capitalized                                         |  |      | 171,694     |   |      |  | 91,807      |      |  |  | 152,550     |   |  |      | 42,298       |   |  |  | 214,034     |  
|Dividends received on investments in shares                                  |  |      | 599,907     |   |      |  |            |      |  |  |            |   |  |      | 2,923,216    |   |  |  | 3,558,680   |  
|Interest capitalized in fixed assets                                         |  |      | (4,292,351  | ) |      |  | (2,295,178  | )    |  |  | (3,813,747  | ) |  |      | (1,057,440   | ) |  |  | (5,350,849  | )
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Earnings                                                                     |  |      | (22,606,050 | ) |      |  | 30,803,973  |      |  |  | (6,428,224  | ) |  |      | (21,539,876  | ) |  |  | 47,024,268  |  
|                                                                             |  |      |             |   |      |  |             |      |  |  |             |   |  |      |              |   |  |  |             |  
|Amount by which fixed charges exceed earnings                                |  |      | 89,529,464  |   |      |  | 45,873,288  |      |  |  | 88,542,066  |   |  |      | 96,481,172   |   |  |  | 16,174,150  |  
|Ratio of earnings to fixed charges                                           |  |      |            |   |      |  |            |      |  |  |            |   |  |      |             |   |  |  |            |  



|(1) | Figures for 2007 are stated in constant pesos as of December 31, 2007. Figures for 2008, 2009, 2010 and 2011 are stated in nominal pesos.
|--- | -----------------------------------------------------------------------------------------------------------------------------------------

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



---

Exhibit 7.1

(2 of 2)



PETROLEOS MEXICANOS SUBSIDIARY ENTITIES AND SUBSIDIARY COMPANIES

Computation of ratio of earnings to fixed charges

(In Thousands of Mexican pesos)(1)



|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|---------------------------------------------------------------------------- |  | ---- | ------------ | - | ---- |  | ----------- | ---- |  |  | ----------- | - |  | ---- | ----------- | - |  |  | ----------- | -
|                                                                             |  | 2011 |              |   | 2010 |  |             | 2009 |  |  | 2008        |   |  | 2007 |            
|U.S. GAAP                                                                    |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Fixed Charges(2):                                                            |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Interest capitalized in fixed assets                                         |  |      | 4,292,351    |   |      |  | 2,295,178   |      |  |  | 3,813,747   |   |  |      | 559,607     |   |  |  | 7,797,815   |  
|Interest expense                                                             |  |      | 62,631,063   |   |      |  | 74,382,083  |      |  |  | 78,300,095  |   |  |      | 74,381,689  |   |  |  | 55,400,603  |  
|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Total interest cost                                                          |  |      | 66,923,414   |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296  |   |  |  | 63,198,418  |  
|Total Fixed Charges                                                          |  |      | 66,923,414   |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296  |   |  |  | 63,198,418  |  
|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Net income                                                                   |  |      | (109,948,897 | ) |      |  | (16,506,920 | )    |  |  | (52,279,935 | ) |  |      | (66,511,844 | ) |  |  | (32,642,076 | )
|Hydrocarbon Income Tax (IRP)                                                 |  |      | (1,120,660   | ) |      |  | 2,417,760   |      |  |  | 2,456,637   |   |  |      | 1,570,288   |   |  |  | 5,967,879   |  
|Income Tax and Others                                                        |  |      | 3,969,740    |   |      |  | 1,938,451   |      |  |  | 6,219,098   |   |  |      | 8,885,312   |   |  |  | 3,226,241   |  
|Profit sharing in subsidiaries and affiliates (income from equity investees) |  |      | 796,398      |   |      |  | (1,540,688  | )    |  |  | 767,228     |   |  |      | (1,815,570  | ) |  |  | (5,791,312  | )
|Minority Interest                                                            |  |      | (210,166     | ) |      |  | (217,437    | )    |  |  | (160,285    | ) |  |      | (140,652    | ) |  |  | 6,089       |  
|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Pretax income from continuing operations before income from equity investees |  |      | (106,513,585 | ) |      |  | (13,908,834 | )    |  |  | (42,997,257 | ) |  |      | (58,012,466 | ) |  |  | (29,233,179 | )
|Fixed Charges(2):                                                            |  |      | 66,923,414   |   |      |  | 76,677,261  |      |  |  | 82,113,842  |   |  |      | 74,941,296  |   |  |  | 63,198,418  |  
|Amortization of interest capitalized                                         |  |      | 171,694      |   |      |  | 91,807      |      |  |  | 152,550     |   |  |      | 22,384      |   |  |  | 311,913     |  
|Dividends received on investments in shares                                  |  |      | 599,907      |   |      |  |            |      |  |  |            |   |  |      | 2,923,216   |   |  |  | 3,558,680   |  
|Interest capitalized in fixed assets                                         |  |      | (4,292,351   | ) |      |  | (2,295,178  | )    |  |  | (3,813,747  | ) |  |      | (559,607    | ) |  |  | (7,797,815  | )
|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Earnings                                                                     |  |      | (43,110,921  | ) |      |  | 60,565,056  |      |  |  | 35,455,388  |   |  |      | 19,314,823  |   |  |  | 30,038,017  |  
|                                                                             |  |      |              |   |      |  |             |      |  |  |             |   |  |      |             |   |  |  |             |  
|Amount by which fixed charges exceed earnings                                |  |      | 110,034,335  |   |      |  | 16,112,205  |      |  |  | 46,658,454  |   |  |      | 55,626,473  |   |  |  | 33,160,401  |  
|Ratio of earnings to fixed charges                                           |  |      |             |   |      |  |            |      |  |  |            |   |  |      |            |   |  |  |            |  



|(1) | Figures for 2007 are stated in constant pesos as of December 31, 2007. Figures for 2008, 2009, 2010 and 2011 are stated in nominal pesos.
|--- | -----------------------------------------------------------------------------------------------------------------------------------------

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