BOSTON, SEPT. 22 -- Aides to Massachusetts Gov. Michael S. Dukakis today acknowledged that his campaign for the Democratic presidential nomination violated federal campaign finance regulations by failing to pay in advance the cost of campaign flights that Dukakis took on corporate jets.

Patricia O'Brien, Dukakis' press secretary, said tonight that a campaign aide discovered the violation last week after press inquiries concerning the governor's use of corporate jets. The campaign had paid all the bills in full by today and voluntarily added 6 percent interest, O'Brien said.

Dukakis was asked about his use of corporate jets in a news conference on Monday, several days after his campaign discovered the violation. He said then that he would continue to use them and that he was confident that his campaign had followed federal election law.

"We have followed the regulations as strictly as possible, to the best of my knowledge, exactly as required," he said at the news conference.

O'Brien said tonight that she did not know when Dukakis learned that his campaign had in fact violated the law or whether he was informed last week that a violation had been discovered.

Dukakis was traveling tonight and could not be reached for comment.

"It was an oversight. We have always complied with the full intent of the law. When we discovered our mistake, we corrected it," O'Brien said. She said the campaign's Sept. 30 filing with the Federal Election Commission will reflect the payments, with interest.

A presidential candidate can use corporate jets for campaigning under strict regulations administered by the FEC. Under the law, a campaign is required to pay first-class fare for each passenger if the flight is between cities that have regularly scheduled commercial service. If no commercial service is available, the campaign must pay the charter rate for the use of a corporate jet. Under the law, the full cost of each trip taken on a corporate jet must be paid in advance, O'Brien said.

Dukakis has used two corporate jets for campaign travel, one owned by the Thomas H. Lee Co. and one owned by the O'Connell Management Co. The owners of the companies, Thomas H. Lee of Lincoln, Mass., and Peter F. O'Connell of Quincy, Mass., have each donated $1,000 to the Dukakis campaign, the maximum allowed under the law.