X0101 EFFECT 33 LIVE 2011-08-31 09:30:00

F-4

0000932782 MEXICAN PETROLEUM 333-175821 0000932785 PEMEX GAS & BASIC PETROCHEMICALS 333-175821-03 0000932784 PEMEX REFINING 333-175821-02 0000932783 PEMEX EXPLORATION & PRODUCTION 333-175821-01