The owners of the New York Mets will be forced to sell the pro baseball team due to huge losses suffered in the Bernard Madoff swindle, the author of a book about the disgraced money manager said on Friday.

The Wilpon family, led by Mets owner Fred Wilpon, lost about $700 million because of Madoff, according to Erin Arvedlund, author of Too Good to Be True, published earlier this month.

Arvedlund said she does not know the terms of the Wilpons' bank loans but said the losses are steep enough that a sale of the baseball team is certain.

It's qualified by when, she said. It's possible they would have to sell by next year.

Fred Wilpon was among thousands of investors defrauded by Madoff, himself a Mets fan. Wilpon bought a stake in the Mets in 1980, raised his share to 50 percent six years later, and purchased the rest with his family and others in 2002.

Madoff pleaded guilty earlier this year to running the biggest investment fraud in Wall Street's history, which prosecutors said bilked investors out of as much as $65 billion. Madoff is serving a 150-year prison sentence.

A Mets spokesman was not immediately available. The team and the Wilpons have repeatedly said the family's Madoff losses will not force a sale or affect the club's operations.

A team spokesman told MarketWatch that Arvedlund's loss projection is inaccurate.

Some bankers have speculated the Wilpons would be forced to sell all or part of the Mets, while others said a sale of part of the Mets cable TV channel SportsNet New York was more likely.

If the team were sold, it would likely fetch more than the $845 million that a group led by Tom Ricketts, a Chicago investment banker and son of the founder of TD Ameritrade Holding Corp, is paying for the Chicago Cubs and other assets, analysts said.

The Mets play in a larger market, control their own sports network and play in a ballpark that opened this season.

In April, Forbes magazine estimated the Mets were worth $912 million, trailing only the New York Yankees among Major League Baseball teams.

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