May oil output slips at Mexico's Cantarell field

MEXICO CITY, June 26 (Reuters) - Crude oil output at Mexico's huge but aging Cantarell offshore field declined in May, according to data published on the energy ministry's Web site on Tuesday.

Cantarell, closely watched by the oil industry after sharp dips in output, produced an average of 1.579 million barrels per day versus 1.592 million bpd in April.

The figure meant Cantarell accounted for just 51 percent of Mexico's overall crude oil output last month.

Over the past year, production has dropped at the field that once produced around 60 percent of state oil monopoly Pemex's oil output.

Analysts are concerned that Pemex will not be able to ramp up yields at newer oil fields like Chicontepec and Ku Maloob Zaap fast enough to compensate for Cantarell's decline.

Pemex is drilling horizontal wells to reach into narrow oil seams as Cantarell grows drier. It forecasts the field will produce an average of 1.526 million bpd over 2007, down 15 percent from the 2006 level.

Mexico is the world's No. 5 oil producer by volume and a top-three supplier to the United States.