WASHINGTON, Dec 20 (Reuters) - General Motors Co (GM.N) said Monday it is extending a production halt at its Orion Assembly plant in Michigan, which makes the Chevrolet Bolt electric vehicle, through the end of February. The largest U.S. automaker in August widened its recall of the Bolt to more than 140,000 vehicles to replace battery modules after a series of fires. Earlier this month, it extended its production shutdown through late January. GM has also indefinitely halted retail sales of new Bolt vehicles. The suburban Detroit plant halted production in August but conducted two weeks of limited production at Orion starting Nov. 1 to help provide courtesy transportation vehicles for customers during recall repairs. GM President Mark Reuss said in October the company was addressing the recall before resuming production. The company said Monday it will continue to prioritize recall repairs and "focus on battery module replacements." The National Highway Traffic Safety Administration has an ongoing investigation into the battery fires. The agency noted in August that all Chevrolet Bolt electric vehicles had been recalled due to the risk of the high-voltage battery pack catching fire. GM disclosed in October that its battery partner, South Korea"s LG Electronics (066570.KS), had agreed to reimburse it for the $2 billion in estimated costs and expenses associated with the Bolt recall. GM and LG Energy Solution are building two joint-venture U.S. battery plants. Reuters reported earlier this month GM has proposed building a $2.5 billion battery plant near Lansing with LG Energy Solution, citing documents filed with the city. The largest U.S. automaker is separately considering a $2 billion overhaul of its Orion Township assembly plant north of Detroit to build next-generation electric vehicles. The total investments could top $4 billion, a source familiar with the plan told Reuters.