'That Jamie Dimon Thing Was Crazy,' Says Jack Welch

The argument that companies should split their chairman and CEO jobs to strengthen corporate governance is "the dumbest idea in the world," former GE boss Jack Welch told CNBC on Tuesday.

Referring to Jamie Dimon's recent fight to keep both roles at JPMorgan, Welch said in a "Squawk Box" interview, "It was crazy to go at the best one in the game." Welch was chairman and CEO of General Electric from 1981-2001.

Last month, Dimon prevailed at the bank's annual meeting when only 32 percent of shareholders voted in favor of a proposal—backed by activist groups after the "London Whale" trading losses—to strip him of the chairmanship. The measure received even less than the 40 percent support it had received last year.

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Welch said the only way he could see splitting the leadership roles at a company is "if you got an ass for a CEO."

"You give the guy the job or the woman the job," he continued. "If you don't like them, throw them out [completely]. I'm not against firing them."

While Dimon got a big vote of confidence, three board members were re-elected by slim margins. David Cote, chairman and CEO of Honeywell; James Crown, who runs his family's Chicago-based investment firm Henry Crown & Co.; and Ellen Futter, president of the American Museum of Natural History, received less than 60 percent approval.

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"That Jamie Dimon thing was crazy," Welch exclaimed, "and then they brought Dave Cote into it."

"Let me tell you about Cote," he continued. "They said he didn't have enough financial acumen? He was on the GE audit staff for 20 years. He's a deeply capable guy in finance. These wackos out there on this stuff don't know anything about it."

JPMorgan lead director Lee Raymond, a former Exxon Mobil CEO, told shareholders at last month's meeting to expect management to reflect on the board's structure in light of the way the votes came down.

By CNBC's Matthew J. Belvedere. Follow him on Twitter @Matt_SquawkCNBC.