Toyota Motor Corp., Mazda Motor Corp. and Denso Corp. plan to jointly launch a new company to develop base technologies for use in electric vehicles, sources close to the matter said Thursday.

Last month, Toyota and Mazda agreed to form a capital tie-up to strengthen cooperation in areas including electric vehicle development, while announcing a plan to begin building cars together in the United States.

By adding auto parts maker Denso, part of the Toyota group, the new firm to be launched by the Japanese entities will aim to make parts that can be used in various types of cars. The addition will also help reduce the costs shouldered by each.

Under the agreement, Toyota will take a 5.05 percent stake in Mazda for ¥50 billion ($442 million) and Mazda will buy a 0.25 percent stake in Toyota equivalent in value to the Mazda shares.