French-Italian automaker Stellantis (STLAM.MI) and South Korean battery maker Samsung SDI (006400.KS) on Monday said they plan to open a second joint-venture plant in the U.S. to build electric vehicle batteries, with a target to start production in 2027.

The companies said the transaction still needs to be finalized, and where the plant will be located is under review. Also, how much will be invested at the site and how many people it will employ will be announced later. The plant will have an initial production capacity of 34 gigawatt hours (GWh)."This new facility will contribute to reaching our aggressive target to offer at least 25 new battery electric vehicles for the North American market by the end of the decade," Stellantis CEO Carlos Tavares said in a statement.

Stellantis, whose brands include Peugeot, Jeep, Ram, Alfa Romeo, Citroen and Opel, has announced plans to reach 100% electric passenger car sales in Europe and 50% car and light truck electric mix in the U.S. by 2030. To achieve that, it has said it wants to secure about 400 GWh of battery capacity.

In 2021, Stellantis said it planned to pump $35 billion into EV production and software globally through 2025. Stellantis said the second U.S. battery plant will be the sixth to support the company's goals.

"The second plant will accelerate our market penetration into the U.S.," Samsung SDI CEO Yoon-ho Choi said in the statement.

In May 2022, Stellantis and Samsung SDI said they would invest more than $2.5 billion to build their first joint battery plant, to open in the first quarter of 2025 in Kokomo, Indiana. That plant will have an initial capacity of 23 GWh, and eventually rise to 33 GWh.

The companies said then the Indiana plant would employ 1,400 people and investment could gradually rise to $3.1 billion.

Stellantis is also building a joint-venture battery plant in Windsor, Ontario, in Canada with South Korea's LG Energy Solution (373220.KS). That plant is set to open in 2024, creating 2,500 jobs and sporting an annual production capacity of over 45 GWh.

In April, Samsung SDI and General Motors (GM.N) said they would invest over $3 billion to build a joint-venture battery plant in U.S., to open in 2026 with an annual capacity of 30 GWh. That plant will also be built in Indiana and employ 1,700 people.

The United Auto Workers union, which has opened negotiations with Stellantis for a new labor agreement covering the automaker's U.S. hourly workers, wants employees at these joint-venture plants being built by GM, Stellantis and Ford Motor (F.N) to be union-represented and paid higher wages.

Samsung SDI shares extended gains after Monday's announcement, rising to as much as 4.1% versus a 0.8% increase in the benchmark KOSPI (.KS11).