HOUSTON, Jan. 25— The body of a former Enron Corporation vice chairman who resigned last May after voicing concerns about the company's financial practices was discovered early this morning inside his Mercedes-Benz after he apparently killed himself.

The former executive, J. Clifford Baxter, had complained last spring to Enron's management team, including Jeffrey K. Skilling, then the chief executive, about questionable accounting measures used by the company, friends and former colleagues said. Mr. Baxter left Enron shortly after that, a decision the company attributed to his desire to spend more time with his family.

Mr. Baxter, 43, was discovered locked inside his car at 2:23 a.m. by a local constable working a private security detail inside the affluent Sweetwater subdivision of Sugar Land, a suburb about 25 miles southwest of downtown Houston.

Police investigators said he had been shot once in the head with a .38-caliber handgun and have concluded that his death was a suicide. The police said he left a note, but they would not release its contents.

Mr. Baxter, married and the father of two children, had apparently been anguished over the problems at Enron and had recently been subpoenaed to testify before Congress. He was also among the many company executives who had been sued by shareholders.

One former business associate, who did not work at Enron, said Mr. Baxter broke down in tears during a telephone call two days ago as they talked about the company. Other former and current Enron colleagues described him as a brash but honest deal maker who reportedly had disagreements with Mr. Skilling and Andrew S. Fastow, the former chief financial officer.

''There was much speculation that there was conflict between him and Skilling,'' said one current Enron manager who often worked with Mr. Baxter. ''And there were rumors that he was objecting to Andy Fastow's transactions.''

Mr. Baxter's name had surfaced last week after Congressional investigators released an internal August memorandum from an Enron vice president, Sherron S. Watkins, to Kenneth L. Lay, who stepped down this week as the company's chief executive.

In the memorandum, Ms. Watkins warned Mr. Lay that the questionable financial structure of a series of secret ''LJM'' partnerships run by Mr. Fastow could destroy the company. She also noted that other executives, including Mr. Baxter, had also expressed concern.

''Cliff Baxter complained mightily to Skilling and all who would listen about the inappropriateness of our transactions with LJM,'' Ms. Watkins wrote.

In light of that memorandum, the Senate Governmental Affairs Subcommittee subpoenaed Mr. Baxter and hoped he would be a helpful witness, Congressional officials said. Investigators from the House Energy and Commerce Committee, also citing the Watkins memorandum, had informed Mr. Baxter's lawyer last week that they wanted to speak to him, but no subpoena had been issued.

''It seemed to us that he was a pretty highly placed insider at Enron who had understood exactly what was wrong there,'' said Representative James C. Greenwood, Republican of Pennsylvania and chairman of the committee's Oversight and Investigations Subcommittee. ''Obviously, we're very sorry he has taken his life, and it adds to the depth of this tragedy.''

A senior law enforcement official said the Federal Bureau of Investigation was looking into Mr. Baxter's death and was investigating whether he had any documents that could be useful in the Enron investigation. On its Web site, ABC News this evening quoted law enforcement sources as saying that Mr. Baxter's suicide note referred to the Enron scandal.

Mr. Baxter's wife declined to comment when a reporter knocked on the door of her home, which is less than a mile from where her husband's body was discovered.

Mr. Baxter's lawyer, J. C. Nickens, issued a statement saying: ''Those who knew Cliff Baxter will miss him. His friends' concern at this moment of personal tragedy is for his family, who wish to be afforded the opportunity to mourn his loss privately in peace and with dignity.''

Mr. Baxter was born in Amityville, N.Y., received a bachelor's degree with honors from New York University and an M.B.A. from Columbia University.

He joined Enron in 1991 and was one of the executives who helped start the company's hugely profitable trading operations. He served as chairman and chief executive of Enron North America, the crown jewel that included the trading business, before being named chief strategy officer for Enron in June 2000. He was named vice chairman four months later.

In 1997, he served as Enron's lead negotiator in the company's acquisition of the Oregon utility Portland General Electric, a role that required him to deal extensively with state regulators who initially sought to block the deal. Mr. Baxter persuaded regulators that the acquisition could benefit consumers and guaranteed that the Portland utility would provide $141 million in rebates to customers.

''My impression of Cliff Baxter was that this was an enormously confident guy who came up here to get the thing done, and he did,'' said an executive of the Portland utility, who would not allow his name to be used. ''The image I had of him at the time is totally at odds with the tragedy today. I mean, he was self assured, he was very friendly. This was practically the last person in the world you'd ever expect to commit suicide.''

The former business associate who spoke by telephone with Mr. Baxter two days ago said he had congratulated him ''for being named among those people who complained about Enron, and all he said was 'Thanks.' Everyone in the executive suite at Enron knew of his complaints.''

This business associate added that Mr. Baxter ''was talking about perhaps needing a bodyguard, though I'm not sure where that idea came from. He said: 'I'm a businessman. Why do I need a bodyguard?' ''

Police officials in Sugar Land have ruled out foul play in Mr. Baxter's death, but a justice of the peace has ordered an autopsy as a precaution.

Mr. Baxter was one of the 29 senior Enron executives named in a shareholder lawsuit seeking compensation for losses due to the collapse of the company into bankruptcy. He sold more than 577,000 shares, the lawsuit said, worth $35.2 million over a three-year period before the bankruptcy. By comparison, Mr. Lay sold 1.8 million shares for $101 million and Mr. Skilling sold 1.1 million shares for $66.9 million.

Financial records indicate that Mr. Baxter's last sale of Enron stock occurred on Jan. 31, 2001, before auditors had expressed internal concerns about the company's accounting practices. By comparison, other executives, including Mr. Lay, sold shares of stock as late as September and October, after financial troubles were apparent.

A high-level executive at Enron, who spoke on the condition of anonymity, said he knew Mr. Baxter casually and described him as well-liked with a good family. He said many people at Enron were feeling pressure from the enormous media coverage and various federal investigations.

''The media has pushed it over the edge,'' the executive said. ''He may have been worried about what else is he going to do. Money is important, but a lot of people are worried about their reputations. Everyone at Enron is getting tarred with the same brush. Everyone is saying: 'What's my future? What's my reputation?' ''

Mark Palmer, a spokesman for Enron, released a statement saying that the company was ''deeply saddened by the tragic loss of our friend and colleague, Cliff Baxter.'' He said he had no knowledge of any disagreements between Mr. Baxter and other executives in the months preceding his resignation. At the time of Mr. Baxter's resignation, Mr. Skilling praised him and attributed his departure to a desire to spend time with his family, Mr. Palmer said today.

''He had a tremendous wit, was an incredibly dedicated employee and was one of the principal architects and figures in the growth of our very successful wholesale operation,'' Mr. Palmer said. ''He wanted to go spend time with his family and his boat. He said: 'The beauty of this one is it really is for personal reasons. I just want to go home and spend time with my family and my boat.' ''

John Baxter