Topeka ? Westar Energy Inc. announced Friday that it had agreed to sell its remaining interest in a Tulsa, Okla., gas company for $262 million, most of which will go to pay down Westar’s debt.

The agreement calls for New York financial services firm Cantor Fitzgerald & Co. to buy 13.7 million shares of ONEOK Inc. from Westar at $19.15 a share.

Westar officials expect the transaction to close Tuesday.

In trading on the New York Stock Exchange, shares of Westar closed up 22 cents, to $19.70. Shares of ONEOK closed up 20 cents, to $19.90.

Under orders from Kansas regulators to improve its financial condition, Westar is trying to raise cash to reduce its $2.9 billion debt. Westar’s management also hopes to convert the company back into a Kansas-only electric utility.

“It’s another piece in the puzzle,” said Westar spokeswoman Karla Olsen. “We’re moving forward.”

David Springe, chief attorney for the Citizens’ Utility Ratepayers Board, a state agency representing residential and small business consumers, said the sale of Westar’s ONEOK stock moved more quickly than expected.

But he added, “It’s unfortunate they’ve had to sell their ONEOK stock. It’s a good asset.”

Westar once owned 45 percent of ONEOK Inc. because of a 1997 deal between the two companies, in which Westar gave ONEOK the assets of its own retail natural gas supply system for an ownership interest in the Tulsa company.

Westar is Kansas’ largest retail electric supplier, with 654,000 customers including Lawrence. ONEOK is the state’s largest retail gas supplier, with 635,000 customers, serving them through its Kansas Gas Service subsidiary.