Toyota Motor Corp. is considering expanding its tie-up with Mazda Motor Corp. to beef up cooperation in the field of green technology, sources close to the matter said Saturday.

Under the plan, Toyota will provide its fuel cell and plug-in hybrid technology in return for Mazda's proprietary Skyactive green technology, the sources said.

Toyota began commercial sales of fuel cell vehicles last year, becoming the world's first automaker to offer the advanced eco-friendly car to general consumers. Mazda is meanwhile attracting strong sales of diesel and gasoline vehicles based on the fuel-efficient Skyactive technology.

Toyota, which is already providing Mazda with hybrid technology, aims to further strengthen its competitive edge by introducing Mazda's know-how in environmental protection, which is expensive to develop, the sources said.

The two automakers are also considering cooperating in component procurement, they said.

Mazda tied up with Ford Motor Co. in 1979 and came under the umbrella of the U.S. automaker in the late 1990s. But ties with Ford have virtually been cut, and Mazda is now producing cars for Toyota at its plant in Mexico.

Toyota owns more than half of the equity in minicar maker Daihatsu Motor Co. and truck maker Hino Motors Ltd., and has a 16.4 percent stake in Fuji Heavy Industries Ltd.