NEW YORK (Reuters) - U.S. pop star Madonna and her husband, British film maker Guy Ritchie, are not planning to divorce, her spokeswoman said on Tuesday, denying media speculation that their marriage is ending.

"There are no divorce plans," Liz Rosenberg, Madonna's publicist, said in a statement emailed to Reuters.

Rumors that the London-based couple planned to split have been circulating for months, fueled most recently by reports that the singer had lined up Fiona Shackleton, a lawyer for Paul McCartney in his bitter divorce from Heather Mills.

The speculation reached a fever pitch last week in London, where the Daily Mirror newspaper dedicated two front pages to the plight of the couple's marriage.

Madonna, 49, and Ritchie, 39, married in December 2000 at Skibo Castle in northeast Scotland. They met at a party hosted by ex-Police frontman Sting and his wife Trudie Styler.

Their son, Rocco, was several months old on their wedding day, and in 2006 Madonna applied to adopt David Banda, a boy from Malawi whose mother died shortly after his birth. The adoption was approved by a Malawian court in May.

Madonna also has a daughter, Lourdes, from an earlier relationship. She was married once before, to Hollywood actor Sean Penn, in the 1980s.

Madonna is one of the most successful rock stars of all time, with global album sales estimated at more than 200 million copies. A multi-Grammy award winner, she was inducted into the Rock and Roll Hall of Fame in March.

Ritchie is best known for his movies "Lock, Stock and Two Smoking Barrels" (1998) and "Snatch" (2000), but he has come in for critical maulings since then, most notably when he directed Madonna in "Swept Away" (2002).

Asked if he would ever work with his wife again, Ritchie told Reuters in an interview in late 2007: "I don't know. We don't want to stick our chins out again."