Mazda Motor Corp. said it has agreed with Fiat Auto S.p.A. to build a new two-seat convertible for the Italian firm's Alfa Romeo brand at its factory in Hiroshima Prefecture from 2015.

Under the accord announced Friday, Mazda will develop the rear-wheel-drive Alfa Romeo Spider based on its next-generation Mazda Roadster, which is known overseas as the MX-5.

The deal is designed to bolster the international competitiveness of the two companies' upcoming sports cars, which will be sold under their respective badges with different exterior designs, Mazda said.

The engines of these Alfa Romeo and Mazda Roadster models will also be different, although Mazda said it will share its Skyactiv fuel-efficiency technology with Fiat to build the new Spider.

Mazda has been searching for a new business ally since the capital affiliation with its former top shareholder, Ford Motor Co., has been weakening. Fiat meanwhile wants to take advantage of the tieup with Mazda to make bigger inroads into the Asian market.