Oct 7 (Reuters) - Stellantis (STLA.MI), the world"s fourth largest carmaker, said on Thursday it would invest $229 million in three plants in Indiana to expedite the development of electric vehicles. The investment, which will retain 662 jobs, will retool three Kokomo plants in Indiana to produce electrified, eight-speed transmissions, Stellantis said. A global clampdown on emissions has forced carmakers to accelerate the development of low-emission technology, even for their low-margin mainstream models. Stellantis, formed earlier this year though the merger of Fiat Chrysler and France"s PSA, made the announcement during an event at the Kokomo Transmission Plant attended by Indiana Governor Eric Holcomb. Oct 7 (Reuters) - Stellantis (STLA.MI), the world"s fourth largest carmaker, said on Thursday it would invest $229 million in three plants in Indiana to expedite the development of electric vehicles. The investment, which will retain 662 jobs, will retool three Kokomo plants in Indiana to produce electrified, eight-speed transmissions, Stellantis said. A global clampdown on emissions has forced carmakers to accelerate the development of low-emission technology, even for their low-margin mainstream models. Stellantis, formed earlier this year though the merger of Fiat Chrysler and France"s PSA, made the announcement during an event at the Kokomo Transmission Plant attended by Indiana Governor Eric Holcomb. Earlier this year, the carmaker announced it would invest more than 30 billion euros ($35.54 billion) through 2025 on electrifying its vehicle lineup.