AFTON, MINN., OCT. 28 -- Republican Jon Grunseth said today he will drop out of the Minnesota governor's race after a woman claimed she had an affair with him while he was married and reports he swam nude with teenage girls.

"There are three things that are extremely important to me -- my wife, my family, first and foremost; the Republican Party, the people of Minnesota," Grunseth said from his home 20 miles east of Minneapolis.

"And the events of the last three weeks have put enormous pressure on the family and I think on the political process and on the people of Minnesota," he said. "I therefore decided to withdraw as the Republican candidate for governor."

Grunseth's campaign was thrown into chaos Oct. 15 by allegations from two women that he swam nude with them while they were teenagers nine years ago. He nearly withdrew from the race Thursday but changed his mind several hours later.

On Saturday, Grunseth acknowledged to the Star Tribune newspaper that he had a "romantic" relationship with 32-year-old Tamara Taylor of Minnetonka, but said it ended "a long time ago -- in the early '80s."

Grunseth, 44, divorced Katharine Winston in 1983 and married his second wife, Vicki, in 1984.

Taylor claimed she had an intermittent sexual relationship with Grunseth from 1980 to 1989 while he was married to his first and second wives.

Grunseth said his affair with the woman ended before he remarried in 1984 and has denied the nude-swimming allegations.

Grunseth said his withdrawal from the Nov. 6 election, in which he hoped to unseat Gov. Rudy Perpich (D), will be effective as soon as the necessary paperwork is processed. The state GOP executive committee can name a replacement for Grunseth on the ballot.

Perpich is seeking a fourth term and state Auditor Arne Carlson, the runner-up in the Sept. 11 GOP primary, reentered the race as a write-in candidate last week.