UPDATE 2-Mexico oil output, exports fall in July

(Adds quote from Pemex chief)

MEXICO CITY, Aug 21 (Reuters) - Mexico's crude oil exports and output fell in July from the previous month as production at the main oil field of Cantarell continues to wane, state-owned energy monopoly Pemex said on Thursday.

Pemex said its July crude oil production was 2.782 million barrels per day versus 2.839 million bpd in June.

Crude exports were down to 1.377 million bpd, from 1.415 million bpd in June, Pemex said.

Pemex is grappling with a steady decline in output at Cantarell in the Gulf of Mexico and recently revised its projections for production levels at the end of 2008 to 2.8 million bpd, down from an initial goal of 3 million bpd.

Crude output peaked at 3.383 million bpd in 2004.

President Felipe Calderon is trying to convince opposition lawmakers to back an energy reform that could give a shot in the arm to Mexico's struggling oil industry.

Officials have said that it will be hard for Mexico to restore oil output to recent levels before 2020, even if the government wins approval from the divided Congress for its plan to boost foreign investment in production efforts.

"Cantarell is falling fast. Not faster than foreseen, but still a strong drop," Pemex Chief Executive Jesus Reyes Heroles said at an event on Thursday.

Mexico's crude oil production dropped 10 percent in the first seven months of 2008 to an average of 2.845 million barrels per day (bpd). Oil exports in the January-July period dropped 16.3 percent to an average of 1.443 million bpd. (Reporting by Cyntia Barrera Diaz and Noel Randewich; Editing by Christian Wiessner)