President Trump said on Friday that Intel, the troubled Silicon Valley chipmaker, had agreed to sell the U.S. government a 10 percent stake in its business, worth $8.9 billion, in one of the largest government interventions in a U.S. company since the rescue of the auto industry after the 2008 financial crisis. At a news conference, Mr. Trump said the agreement had come out of negotiations last week with Lip-Bu Tan, Intel's chief executive. "I said, 'I think it would be good having the United States as your partner.' He agreed, and they've agreed to do it," Mr. Trump said. "And I think it's a great deal for them." Intel said the United States would invest $8.9 billion in its stock, on top of $2.2 billion that the government has paid the company under the CHIPS and Science Act, a federal program signed into law in 2022 that delivered billions in grants to revive U.S. semiconductor manufacturing. The government will not take a board seat or have other governance rights at Intel.