The state-owned company could begin imports of light and intermediate crudes as early as this year to improve production of higher-value refined products like gasoline, Jose Manuel Carrera, chief executive officer of its P.M.I. Comercio Internacional oil trading arm, said in an interview.

Mexico, the world's 10th-largest crude oil producer, has very rarely imported the commodity, instead preferring a decades-long self-sufficiency. Still, it must import about half of its gasoline due to flagging refinery output at home.

"Pemex is analyzing in great detail how to optimize the diet of its national refining system with imported crudes ... both light and intermediate," Carrera told Reuters.

P.M.I. officials say crude imports would not exceed 20 percent of a refinery's crude-processing capacity.

The company also aims to produce less fuel oil as Mexico's power sector increasingly substitutes cheaper natural gas for the generation of electricity, said Carrera.

"Given the changing structure of demand in Mexico, it's important to adjust the diet of our refineries," he added.

Carrera said the timing of any crude imports remained unclear. He emphasized that P.M.I. was looking at light and intermediate grade crudes from West Africa, Colombia and the Middle East, not just the United States.

The head of Pemex's refining unit said last year that any light crude imports to boost fuel output would only make sense in the next few years, before major new upgrades are completed.

Sector analysts say those projects, a $11 billion push to install deep conversion coking units at the company's three biggest refineries, will probably be delayed through 2020.

MORE OIL TO INDIA, JAPAN

Mexico is the No. 3 crude supplier to the United States, but export volumes to its neighbor have fallen by 43 percent since 2004 to 850,000 bpd last year, the lowest level in two decades, according to the U.S. Energy Information Administration.

Light sweet crude output in the United States, the destination for about 70 percent of the 1.19 million barrels per day (bpd) of crude Pemex shipped last year, is booming because of surging volumes at major shale plays like the Eagle Ford formation in Texas.

With the United States increasingly energy-independent, Pemex needs new markets.

Analysts expect competition to intensify for heavy crudes in the Gulf coast refining sector in Texas and Louisiana, where most Mexican shipments go, as more West Canadian Select heavy crude is delivered to refiners over the next few years.

That could push out Mexican heavy crudes.

P.M.I. plans to lift crude export revenue beyond the $42.7 billion in 2013. That was down 11 percent from 2012 as the price of Pemex's main heavy crude export, Maya, slipped and oil output slowed 5.3 percent, according to the company's annual report.

By the end of 2014, Mexico's export volumes to India are expected to grow by 50,000 bpd from around 105,000 bpd now, said P.M.I. Crude Oil Director Tomas Banos.

P.M.I. expects crude exports to Japan to double to 60,000 bpd by the end of 2014 because of two new clients, Banos added.

A one-time sale of 1 million barrels to refiner Cosmo Oil Co (>> Cosmo Oil Co Ltd) announced last month is the first Mexican crude bound for Japan in 11 years. Carrera said he also expected higher sales to European and U.S. West Coast clients, but did not say which.

"We want to sell barrels of Mexican crude to the Arabian Peninsula," said Banos, adding that shipments should begin this year or next.

Banos said P.M.I. expected crude shipments to China, which began in 2010, to remain steady in 2014 at about 30,000 bpd. They are unlikely to grow beyond that due to adjustments Chinese refineries must make to process more Mexican crudes.

In December, Mexico ended Pemex's 75-year monopoly on a wide range of oil industry activities, including exploration and production as well as first-hand gasoline sales.

It is unclear whether P.M.I. will remain Mexico's only legal crude-sales agent when new exploration and production contracts start in the next couple years, said Carrera.

This, he added, is a key detail of the fine print of the reform Congress is debating.

"There are lawmakers who say that each operator should do as they see fit in an open market," said Carrera. "But on the other side, there are lawmakers and currents that have suggested that one (national sales agent) makes sense."

If BP Plc (>> BP plc), Exxon Mobil Corp (>> Exxon Mobil Corporation) and other companies that may enter post-reform Mexico had to turn over any crude production there to a state-run sales agent, they would lose out on lucrative marketing revenue.

President Enrique Pena Nieto pitched the new contracts allowed under the reform, including production-sharing agreements and licenses, as necessary tools to lure significant streams of private investment and boost lagging oil production.

Mexican crude output averaged 2.52 million bpd in 2013, down a quarter since hitting a peak of 3.38 million bpd a decade ago.

(Reporting by David Alire Garcia and Ana Isabel Martinez; Editing by Dave Graham and Lisa Von Ahn)

By David Alire Garcia and Ana Isabel Martinez

Stocks treated in this article : Exxon Mobil Corporation, Cosmo Oil Co Ltd, BP plc