Authorities in Europe have launched a manhunt for a decorated U.S. Marine veteran of the Afghan war who ran off to France with a 12-year-old British schoolgirl he met on the Internet, cops said Monday.

The girl flew from London to Paris on Saturday with Toby Studabaker, 31, without telling her parents, said British cops — who added that the pair had been corresponding by letter and e-mail for a year.

Studabaker was arrested in Michigan five years ago on a criminal sexual-misconduct charge involving a family member, The Times of London reported on its Web site. But prosecutors decided there wasn't enough evidence to try the case, the paper said.

"We're very concerned," a British police spokeswoman said. "She has gone abroad with an older man whom her parents don't know, and she is only 12, so she is very vulnerable."

The girl's parents, who live in northwest England, yesterday issued a desperate plea: "If she is with Toby, please do the right thing and bring her home to us," they said.

Studabaker, a former Bible scholar who served with an elite anti-terrorism unit in Afghanistan, was discharged as a lance corporal on June 30 after deciding not to re-enlist, said Lt. Kate Vandenbossche, a spokesman at Camp Lejeune, North Carolina, where he was based.

The stocky ex-Marine, from Constantine, Mich., flew from Detroit to Amsterdam and then to Manchester, near the girl's home, on Saturday. They then flew to Paris via London, cops said.

Studabaker is trained in the use of shoulder-launched multi-purpose assault weapons and other high-tech systems, said Vandenbossche. He was awarded the Sea Service Medal and National Defense Ribbon.

The girl's parents describe her as a good, quiet student who has lots of friends and loves punk rock and the Internet.

But they told The Times they'd become worried about her regular 11-hour sessions on the Internet.

"As far as we were aware she was chatting to people of her own age," said her mother.

They said they saw her last at 7:30 a.m. Saturday when she told them she was meeting friends.

"She went to the door, said 'bye,' and that was the last we saw of her," said her father.

The girl's cell phone was switched off and she had taken a school bag with her passport and some clothes.

"Please, we just want you back," her parents said in a statement. "We are not angry with you — we love you very much and just want you to come home."

Added her mother, "I'm praying that once this man knows how old she is, he will do the right thing. I honestly believe that [my daughter] thinks that this man is a lot younger."