LOS ANGELES (Reuters) - DNA analysis has failed to establish a link between the skyjacker dubbed D.B. Cooper and a new suspect in the decades-old case, but the results do not rule out that he may have been the culprit, the FBI said on Monday.

The FBI's disclosure came days after an Oklahoma woman came forward to say she believes her late uncle, Lynn Doyle Cooper, was the mysterious man who hijacked a Pacific Northwest flight in 1971 and then vanished.

The FBI declined to say if the suspect whose DNA was checked against that of the hijacker was Lynn Doyle Cooper, but the circumstances appeared to match.

The FBI has a necktie the hijacker is believed to have worn, and DNA taken from a family member of the latest suspect did not match the DNA on the tie, said FBI Special Agent Fred Gutt, a spokesman for the bureau's Seattle office.

"He's not been ruled out," Gutt said.

That is because there are strands of DNA from three different people on the necktie, which could have been bought at a second-hand store, Gutt said.

"We don't even know if (any of the strands of DNA) belong to the hijacker," he said.

A man who in 1971, under the name Dan Cooper, bought a plane ticket in Portland, Oregon, for a Seattle-bound flight on Northwest Orient Airlines seized control of the plane by claiming to have a bomb.

He freed passengers after landing in Seattle in exchange for $200,000 from the airline. Then he ordered the plane to take off again, and jumped out of the aircraft with the cash and a parachute.

The suspect name "D.B. Cooper," rather than "Dan Cooper," came from media reports about the case.

Marla Wynn Cooper, 48, of Oklahoma City said last week that she recalls her uncle, Lynn Doyle Cooper, arriving bloody and bruised to a family gathering soon after the hijacking.

She also said that conversations she overheard at the time between him and another family member suggest that they had plotted the hijacking.

Marla Wynn Cooper said she believes her uncle died in 1999. She said on Monday that the FBI would like to run more tests, to compare fingerprints lifted in 1971 from the hijacked airliner to any prints her uncle may have left at the last place he lived, a home near Reno, Nevada.

But first, investigators would need to obtain fingerprints from that home, she said.

"There's no way to prove the case unless they do that," Marla Cooper said.

(Reporting by Laura L. Myers and Steve Olafson, writing by Alex Dobuzinskis: Editing by Dan Whitcomb and Cynthia Johnston)