A Senator examining the stunning collapse of Enron Corp accused the company Thursday of not cooperating with his probe, while federal energy regulators launched yet another investigation into the once high-flying energy trader.

Sen. Byron Dorgan, who heads the Senate Commerce subcommittee on consumer affairs, said Enron had not cooperated with the panel's inquiry into its downfall. Elsewhere, the Federal Energy Regulatory Commission (FERC) launched a probe into allegations that Enron unfairly boosted wholesale power prices during California's power crisis last year.

Former Enron suitor Dynegy Inc took control of the Northern Natural Gas pipeline, giving it half the pipeline system Enron was counting on to help pay its creditors and survive a bankruptcy court reorganisation. Enron has sued Dynegy over the pipeline.

The Senate Finance Committee, one of at least nine congressional committees probing Enron's demise, asked three federal agencies that help corporations operate overseas for details of any assistance they may have given Enron.

The impact of Enron's descent into the largest bankruptcy in US history continued to spread. Microsoft Corp's internet unit, MSN, said its plans to sell high-speed access to homes would be delayed by Enron's woes. Enron had been providing the backbone for MSN's expansion of its high-speed access and services.

Alliance Capital Management Holding LP, which was the largest shareholder in Enron, reported a 10 per cent drop in fourth-quarter profits. Power producer Calpine Corp which with other power producers has faced increasing scrutiny from investors and creditors since Enron's Dec 2 bankruptcy filing saw fourth-quarter earnings tumble 23 per cent.

Thousands of workers have lost their jobs since Enron filed for bankruptcy amid questionable accounting practices failed investments and the impact of off-balance sheet activities. Many former and current employees saw the value of Enron shares held in retirement plans become virtually worthless.

The Enron Corporation is not cooperating with the committee's request for information," said Dorgan, a North Dakota Democrat and subcommittee chairman.