In a sign of mounting frustration among Republicans in Washington, Representative Pat Tiberi of Ohio, a senior lawmaker with close ties to his party’s leaders, is expected to resign and take up an executive post with a business group in his home state, according to three Republicans briefed on his plans.

An abrupt departure by Mr. Tiberi, who is an influential member of the House Ways and Means Committee, would signal a deepening level of discontent among mainstream Republicans in Congress. Despite holding Congress and the White House, Republicans have so far failed to achieve longstanding policy goals like overhauling the tax code and repealing the Affordable Care Act.

Mr. Tiberi, 54, could announce his plan to leave Congress as soon as this week, Republican officials said, though it is unclear when he intends to vacate his seat. Two Republicans who were briefed on Mr. Tiberi’s decision said he had indicated that he plans to join the Ohio Business Roundtable, a business consortium that announced this summer that it was searching for a new president.

Mr. Tiberi did not respond to a phone call or a text message seeking comment on Wednesday night. But some of Mr. Tiberi’s colleagues said that the grind of their jobs had gotten no better since Donald J. Trump’s election last year, giving Republicans full control of Washington.