SEOUL, South Korea: South Korean battery maker Samsung SDI will acquire General Motors' 49.99 percent stake in their Indiana battery joint venture, ending the partnership after citing slower-than-expected growth in electric vehicle demand.

Samsung SDI said in a regulatory filing on August 11 that it plans to use the wholly owned unit, SDI-GM Synergy Cells Holdings, to meet demand for batteries across a range of applications, including energy storage systems (ESS) and electric vehicles.

The company said its existing investment plan would change following the transition to a wholly owned business, although specific investment plans have not yet been finalized. It said further details would be disclosed in accordance with regulatory requirements.

"The ownership change was made in consideration of market changes since the joint venture was announced, including the slower-than-expected growth of EV demand. The two partners have now decided to seek other forms of cooperation other than the joint venture," Samsung SDI said in a statement.

Separately, Samsung SDI said it has signed an agreement with GM to jointly develop next-generation prismatic batteries for potential future EV applications.

Reuters reported earlier this year that construction at the Indiana plant had slowed amid weak demand for electric vehicles.

GM and other automakers pulled back on EV manufacturing after the loss of a US$7,500 federal tax credit last September. While automakers continue to build and sell electric vehicles, they have reduced factory output to better match demand.

The joint venture was announced two years ago and was initially expected to have an annual production capacity of 27 gigawatt hours, with mass production targeted to begin in 2027.

In March, GM and LG Energy Solution also announced plans to convert another EV battery plant in Tennessee to manufacture batteries for energy storage systems.