In late January, about 40 Wall Street financiers packed into a private dining room at III Forks Steakhouse in Houston for an update on the troubled multibillion-dollar merger of the pipeline companies Energy Transfer Equity and the Williams Companies.

With shares of Energy Transfer down 50 percent since the transaction was announced in September, the investors interrogated Energy Transfer’s chief financial officer, Jamie Welch. He tried to assuage the analysts and investors, assuring them that his company was committed to closing the deal.

Less than 10 days later, Energy Transfer fired Mr. Welch.

Mr. Welch’s ouster stunned most investors, causing Energy Transfer’s stock to drop 42 percent in one day, but not everyone was surprised. Since December, Mr. Welch, a former investment banker who helped sculpt the $38 billion acquisition, had been actively trying to recut the deal, or get out of it entirely.