Panasonic Corp. will increase domestic production of lithium-ion batteries used for automobiles to meet robust demand in the United States, company sources said Thursday.

The struggling electronics maker will resume operation of idled lines at an Osaka factory, which produces batteries for U.S. automaker Tesla Motors Inc., as early as January, while another factory in Osaka will reopen by the end of next fiscal year after it was shut down in March, according to the sources.

Panasonic’s small battery business, including lithium-ion batteries, posted an operating profit of ¥4.1 billion in the April-June quarter.