General Motors withdrew Monday from a Trump administration-backed challenge to California's fuel economy rules and endorsed President-Elect Joe Biden's policy for boosting usage of electric autos. GM and other automakers in October 2019 announced they supported a Trump administration challenge to California, arguing that fuel economy rules should be set at the federal level. But on Monday, the US auto giant said it was "immediately withdrawing" from the lawsuit and inviting "other automakers to join us," according to a letter from GM Chief Executive Mary Barra to environmental groups. jmb/cs