Mexican state-owned oil monopoly Petroleos Mexicanos needs to invest $40 billion over the next five or six years to expand its refinery capacity, CEO Emilio Lozoya said.

Mexico, one of the world's largest oil producers, must import fuel to meet domestic demand due to the limitations of its refinery network.

In a ceremony Wednesday to show appreciation for Pemex's refinery workers, Lozoya said the company must "creatively" adapt to changes in the global oil industry to become increasingly agile, efficient and profitable.

Pemex processed an average of 438,000 barrels of gasoline a day at its six refineries during the year's first 10 months, but it still needed to import an additional 344,000 barrels per day to cover domestic demand. EFE