Mexico, Shell Form Deal to Run Refinery : Energy: Petroleos Mexicanos will buy a 50% stake in Houston plant, ship crude there for processing and then send it back across the border.

Shell Oil Co. and Mexico’s state-owned oil monopoly announced Wednesday that they will form a joint venture to bring Mexican crude oil to Texas and refine it into unleaded gasoline to be sent to Mexico.

Pemex, or Petroleos Mexicanos, will buy 50% of a Shell oil refinery near Houston, which can process 225,000 barrels of crude a day.

The arrangement will provide Shell with a reliable, nearby source of more than 100,000 barrels of crude daily. The refinery will return to Mexico 45,000 barrels of unleaded gasoline a day, meeting more than half the country’s growing demand.

As part of the effort to combat air pollution in Mexico City, buses, taxis and private cars were required to have catalytic converters for the first time in 1991, increasing the need for unleaded gasoline.

“This would seem to be a rather nifty way to get around” Mexico’s ban on foreign investment in its oil industry, said Peter C. Beutel, energy director of the Pegasus Econometric Group, a Hoboken, N.J., consultant.

“The Mexicans can certainly use American refining technique, and its equipment and capacity,” Beutel said, “and Shell can benefit from buying cheaper short-haul crude instead of long-haul crude” from the more-distant and less politically stable Middle East.

The heavy Mexican oil--called Maya crude--will replace oil that Shell has been buying on the open market. As part of the deal, improvements will be made to the refinery to allow it to handle more heavy crude.

Shell will manage the joint venture and continue to run the refinery, said Eydie Pengelly, a Shell spokeswoman.

Mexican gasoline imports more than doubled last year, to $672 million, mainly because Pemex was unable to keep up with demand for unleaded gasoline. Most of last year’s almost 69,000 barrels a day of imported gasoline was unleaded.