HOUSTON – Kenneth Lay and Jeffrey Skilling, who built Enron Corporation into the nation’s seventh-largest company and then drove it into bankruptcy, were convicted of orchestrating a fraud that made the energy trader the symbol of corporate deceit in America.

Jurors in federal court in Houston deliberated six days before finding Lay, Enron’s former chairman, and Skilling, its former chief executive officer, guilty of fraud, conspiracy, and other charges for lying to investors about the company’s finances. The panel heard four months of testimony before reaching its verdict.

“The government will not let corporate leaders violate their trust and get away with it,” Sean Berkowitz, head of the Justice Department’s Enron Task Force, which conducted the prosecution, said. “You can’t lie to shareholders and put yourself in front of your employees’ interests.”

Lay, 64, and Skilling, 52, face at least 25 years each in prison after being convicted of using off-the-books partnerships to disguise Enron’s debts. Skilling faces additional jail time over his conviction for using inside information to sell Enron stock. Lay was also convicted on bank fraud charges after a trial that U.S. District Judge Sim Lake held without a jury while the panel in the main case deliberated.

“Obviously I’m not real happy with this,” Skilling said in the courtroom after the verdict.”It is what it is.” Skilling maintained his innocence and his lawyer, Daniel Petrocelli, said he would appeal.

Judge Lake said he would sentence the defendants on September 11. Skilling is allowed to remain free on a $5 million bond and doesn’t have to be put in “home confinement” as prosecutors sought, Judge Lake said.

Lay surrendered his passport after the judge said he wasn’t allowed to leave the courthouse until he did so. Lay posted a $5 million bond, co-signed by his wife and children. He’s restricted to living in Colorado and the southern district of Texas, and the routes to and from those places.

“I firmly believe I’m innocent of the charges against me,” Lay said outside the courtroom. “We believe God in fact is in control and he does indeed work all things for the good.”

Both men face spending the rest of their lives in prison if they are given maximum sentences. After the verdict was announced, the color drained from Lay’s face and his wife and daughter burst into tears. Skilling’s wife wasn’t in the courtroom.

“We’ve had a trial, and obviously it did not come out the way we hoped,” Mr. Petrocelli said. “It doesn’t change our view of what happened at Enron. And it certainly doesn’t change our view of Jeff Skilling’s innocence.”

Enron, once the world’s largest energy trading firm, had more than $68 billion in market value before its December 2001 bankruptcy filing wiped out thousands of jobs and at least $1 billion in retirement funds virtually overnight. Investors suing over the company’s collapse claim accounting fraud at the Houston-based firm caused at least $25 billion in losses.

“I think investors can feel validated in that the legal system worked here,” a partner at Sichenzia Ross Friedman Ference, Mark Ross, said. “On a bigger picture,it will instill confidence back in the capital markets in America.”

In the wake of Enron’s meltdown, government prosecutors cracked down on corporate crime. CEOs of WorldCom Incorporated, HealthSouth Corporation, Adelphia Communications Corporation, and Rite Aid Corporation were prosecuted for accounting fraud or looting company treasuries. All were convicted of fraud except the Health-South founder, Richard Scrushy, who now is on trial on unrelated bribery charges in Alabama.

We should “punish the bad apples and that’s obviously what happened in Texas,” Senator Sarbanes, a Democrat of Maryland, said. Mr. Sarbanes is the co-author of the Sarbanes-Oxley Act of 2002, passed to improve corporate reporting. “They undermined confidence in our markets.”

The eight-woman, four-man jury convicted Skilling on 19 of the 28 charges against him while finding Lay guilty of all of the six counts against him. The government presented 25 witnesses against the men, including a parade of former Enron executives.

“It’s safe to say each of them is facing north of 20 years real jail time,” a former federal prosecutor and co-author of “Federal Sentencing for Business Crimes,” Kirby Behre, said. The calculation of the size of the fraud will play a part in determining the exact sentence. “There’s going to be a mini-trial on sentencing issues.”

Prosecutors should feel vindicated as well, Mr. Behre, now a partner at Paul Hastings Janofsky & Walker in Washington, said. “This case epitomizes a new paradigm of corporate criminal prosecutions. We now hold the highest-level executives responsible for the misconduct of the company. These two guys are as high as they get.”

Enron contributed nearly $6 million to federal parties and candidates between 1989 and 2001, more than two-thirds to Republicans, according to OpenSecrets.org, the Web site of the Center for Responsive Politics.

More than $2 million of that money came during the 1999-2000 election cycle, when the company became one of the biggest backers of President Bush’s bid for the White House. Lay personally raised at least $100,000 for the campaign, and Mr. Bush used to refer to him by the nickname “Kenny Boy.”

A White House spokesman, Tony Snow, said yesterday that the Justice Department was to be congratulated for concluding a “highly complex” case. “The administration has been pretty clear, there’s no tolerance for corporate corruption,” Mr. Snow said when asked about the guilty verdicts.