Topeka ? Federal authorities have opened an investigation into Westar Energy, capping a week of setbacks for the state’s largest electric utility.

The company was subpoenaed by a federal grand jury here for documents and testimony related to the annual shareholder meeting and use of aircraft leased by Westar’s subsidiaries, according to a filing made by Westar with the Securities and Exchange Commission.

The probe then expanded with additional subpoenas through the U.S. Attorney’s Office for information on Westar chief executive David Wittig, further documents on aircraft “and the company generally,” according to the filing, which was released Friday.

“The company intends to cooperate with the United States Attorney’s Office in this manner,” the Westar statement said.

In the filing, Westar said it had appointed a special committee to investigate matters before the grand jury. The committee includes Westar board member Frank Becker, who is president of Becker Investments Inc. in Lawrence. The committee hired Debevoise & Plimpton, a global, corporate law firm, as its legal counsel.

Neither Westar officials nor Becker returned telephone calls Friday from the Journal-World. A spokeswoman for Debevoise & Plimpton in New York said the law firm would have no comment. A spokeswoman with the U.S. Attorney’s Office refused to confirm or deny the existence of an investigation.

A Westar spokesman told The Associated Press the company would make no comment explaining its SEC filing about the grand jury investigation.

“We can’t elaborate on this document at this time,” said spokesman Doug Lawrence. “It will have to stand on its own.”

‘Just amazing’

News of the probe sent shock waves through the state Capitol. Wittig and Westar officials are high rollers in Kansas political and social circles.

But the company has taken a steep plunge from a high-water trading mark of more than $40 per share four years ago on the New York Stock Exchange; on Friday it closed at $9.96 cents per share, down 29 cents for the day.

“It’s just amazing,” said Walker Hendrix, who has fought Westar for years as the consumer counsel for the Citizens’ Utility Ratepayer Board.

Westar provides electricity to nearly 650,000 Kansans, including Lawrence under its KPL division.

On Thursday, state utility regulators took an unprecedented step in saying it would order Westar to restructure itself because the company had dumped more than $1 billion of debt on utility ratepayers. The debt was the result of financial problems with business ventures outside the utility, the Kansas Corporation Commission said.

Rosemary Foreman, a spokeswoman for the KCC, said Friday’s revelation about the grand jury investigation would not affect the KCC order, which will be officially formulated next month.

“We’re continuing to move forward with the case that is before the commission,” she said.

Earlier in the week, Westar announced it was scaling back its severance agreements with Wittig and other top executives, should they leave. But the development drew fire from consumer advocates because Westar refused to release details about the so-called golden parachutes that are worth millions of dollars.

Plea to the feds

And on Friday another development sought to rein in Westar.

KCC Chairman John Wine wrote a key congressman and the Kansas congressional delegation, urging them to try to block a proposal in Congress that would make it easier for Westar to leave nonutility debt on utility customers.

“I believe the continued oversight of Westar by both the Federal Energy Regulatory Commission and federal securities regulators, as well as the KCC, is needed to protect the ratepayers of retail electric service in Kansas and the shareholders of Westar,” Wine said.

High-flying probe

On the issue of the subpoenas, state consumer officials have long wanted to get their hands on details of how top-level Westar officials were using company aircraft.

In Westar’s request for a rate increase last year, consumer advocates argued that Westar executives were using the company aircraft for nonbusiness purposes.

The KCC had Westar turn over flight data, but did not allow consumer groups to depose officials to get more information about those flight logs, according to Hendrix. Under an agreement with Westar, those flight logs remain closed to the public.

Hendrix said he had heard numerous anecdotal stories about alleged misuse of company aircraft, such as executives using the aircraft for personal reasons or vacations and not reimbursing the company.

He also said he received several anonymous letters urging him to investigate the aircraft. One read, “Check Westar expense jet travel and passengers  friends and family vacations.”