General Motors Co. thwarted a $15 million settlement between the company’s bankruptcy trust and thousands of plaintiffs that would have forced the automaker to contribute $1 billion in stock, prompting claims of a secret plot cooked up behind closed doors, Bloomberg News reported yesterday. The now-derailed deal was intended to resolve hundreds of personal-injury cases stemming from GM’s faulty ignition switches, as well as a class-action suit over millions of vehicles that allegedly lost value due to a series of recalls in 2014. In a letter filed yesterday in U.S. Bankruptcy Court in Manhattan, lawyers for the plaintiffs said that GM conspired with the trust to block the accord after GM previously accused the trust and the plaintiffs of engaging in the same behavior in negotiations last week. GM "undertook a secret, contrived scheme to undermine the settlement agreement through a campaign of threats, intimidation and payoffs," plaintiffs attorney Edward Weisfelner said in the letter, which was dated Wednesday. Detroit-based GM had fumed at the settlement and promised a court fight over what it called a "contrived scheme" to extract the $1 billion in stock. The company has been fighting to move on from the litigation after previously paying at least $870 million to settle claims and an additional $900 million to the Department of Justice to resolve a criminal probe.