Rep. Randy "Duke" Cunningham (R-Calif.), a Vietnam War fighter pilot whose house was raided by the FBI this month in an investigation of his ties to a defense contractor, announced yesterday that he will not seek reelection but will serve out his term.

"I learned in Vietnam that no one person is more important than the mission, and I do not intend to forget that lesson now," the eight-term House member said in San Marcos, Calif.

The announcement made Cunningham, 63, the first casualty of a growing controversy over the ethical conduct of a number of senior House members, including Majority Leader Tom DeLay (R-Tex.). Democrats have vowed to try to use the issue before next year's midterm elections to make a broad case against Republican abuse of power, but Republicans say Democrats are equally vulnerable.

"The time has come for me to conclude the public chapter of my life," Cunningham said. "I do not believe that a political campaign in the midst of such an investigation is in the best interests of my family or my constituents."

The case was unusual for the swiftness and variety of questions that piled up against Cunningham after a June 12 report in the San Diego Union-Tribune that said he had sold his house to a defense contractor who had immediately put it back on the market, eventually taking a $700,000 loss. Cunningham is on the subcommittee on defense appropriations, and even he has acknowledged that the transaction looked like a sweetheart deal.

"I fully recognize that I showed poor judgment when I sold my home in Del Mar to a friend who did business with the government," Cunningham told supporters. "I should have given more thought to how such a transaction might look to those who don't know me. I have spent an entire life building a reputation of integrity and honesty. It pains me beyond words that I have jeopardized your trust."

Subsequent reports revealed that the same contractor -- Mitchell J. Wade of D.C.-based MZM Inc. -- had allowed Cunningham to live rent-free on a yacht on the Potomac River. The boat was named the Duke Stir. On July 1, agents from the FBI, Internal Revenue Service and Defense Criminal Investigative Service descended on Cunningham's house in Rancho Santa Fe, Calif., and on Wade's house, boat and office in Washington.

On Wednesday, the Associated Press reported that two members and two employees of the Capital Yacht Club in Washington, where Cunningham had lived, were subpoenaed to testify before a federal grand jury in San Diego. Lawyers said it will be an extensive investigation.

Friends said Cunningham and his wife, Nancy, made the decision and were not pressured by Republican leaders. Rep. Thomas M. Reynolds (R-N.Y.), chairman of the National Republican Congressional Committee, said in a statement that Cunningham's "career in Washington was defined by straight talk and hard work," and that with his announcement, he had done "for his party what he has always done for his country: He put the interests of others above his own ambitions."

Cunningham was a Navy fighter ace in Vietnam, receiving the Purple Heart and many other decorations, and later trained pilots at the Miramar Naval Air Station. He retired from the Navy in 1987 and was elected to Congress in 1990.

Cunningham, speaking outside the library at California State University at San Marcos, said that he will be vindicated but that he "will not ignore the damage to my standing in this community."

Potential candidates from both parties were circling his seat. President Bush took 55 percent of the vote in Cunningham's district in November, a healthy percentage for a Republican in California, and GOP officials said they are confident the seat will remain in the party's control.

Cunningham also has a Web business called Top Gun Enterprises Inc. that had sold books and knives, perhaps improperly carrying the congressional seal. The offerings were recently removed. He said he will sell his house in Rancho Santa Fe and donate a portion of the proceeds to three San Diego charities in an effort to dispel "any question in the minds of my friends and supporters about whether I improperly benefited from my work as their representative in Washington."

Rep. Randy "Duke" Cunningham with his wife, Nancy. He is under investigation for his dealings with a defense contractor.