Investors led by Kohlberg Kravis Roberts & Co. and TPG, formerly Texas Pacific Group, expect to close the deal in the fourth quarter. TXU shareholders approved it in Friday.

The major obstacle remaining is the completion of a financing package from major Wall Street banks.

Bankers have grown reluctant to finance big private acquisitions because they've had trouble lining up investors to help back the deals.

KKR and TPG, which arranged their financing at the height of the buyout binge earlier this year, have declined to comment on financing. TXU Chief Executive C. John Wilder told The Associated Press on Friday that he had no indications the investors were having any problems completing their financing.

It would be one of the largest private buyouts ever.

The Nuclear Regulatory Commission approval was required to transfer operation of TXU's Comanche Peak reactor to the new owners. TXU said no outside groups filed to protest the transfer.

Some consumer and environmental groups in Texas oppose the deal, charging that debt taken on in the buyout will lead to higher rates. They are pushing the buyers to promise lower electric rates for the next several years.

Dallas-based TXU produces, distributes and sells power to 2.1 million residential and business customers.

TXU shares rose 62 cents to $68.04 in morning trading Tuesday -- 1.7 percent below the $69.25 price per share that KKR and TPG have offered to pay for the company.