Jack Welch, the former head of General Electric, delivered a blunt rebuke to his handpicked successor yesterday, saying the failure of the conglomerate's earnings to meet market expectations last week was a "screw-up" that left Jeffrey Immelt with a "credibility issue".

Mr Welch's rare criticism of Mr Immelt, made yesterday on a television channel owned by GE, will increase pressure on the company's senior management to restore investor confidence in the US financial and industrial conglomerate.

Shareholder anger at Friday's news that first-quarter earnings were well below Wall Street expectations was compounded by the fact that Mr Immelt had repeated the company's guidance for a 10 per cent profit growth in mid-March. GE shares fell 13 per cent on Friday and have only slightly pared their losses since.

"Here's the screw-up: you made a promise that you'd deliver this and you miss three weeks later,'' Mr Welch said yesterday on GE-owned CNBC. "Jeff has a credibility issue. He's getting his ass kicked. He apologised. Things happen fast.''

Mr Immelt has said the market conditions that accompanied the implosion of investment bank Bear Stearns - days after he repeated his profit forecast - had made it impossible for GE to make its numbers.

Mr Welch defended Mr Immelt's record since taking over the top job in 2001 and rejected calls from analysts and investors for a break-up of GE, saying its business model "isn't broken".

"Let's put GE in perspective,'' he said. "At 50,000 feet, stare at a company that made $4bn-plus (£2bn-plus), down 6 per cent over a glitch in financial services, going to make over $20bn this year. You guys are crazy. The plane landed and it was circling for a while; it landed and the passengers got out safely."

However, he issued a veiled warning that Mr Immelt and his top management team could not afford to further disappoint investors.

"I do think Jeff was doing his job and he got caught here. He'll never make that mistake again,'' Mr Welch, who led GE between 1981 and 2001, said. "I would be shocked beyond belief and I'd get a gun out and shoot him if he doesn't make what he promised now.''

Under Mr Immelt, GE shares have been largely flat as investors have questioned the company's growth potential and strategy. GE's management has been frustrated at the shares' performance and have pointed out that the company is currently much bigger and faster-growing than the one they inherited from Mr Welch.

GE declined to comment about Mr Welch's criticism.