A famed Las Vegas sports gambler pleaded not guilty on Wednesday to charges that he engaged in an insider trading scheme that generated more than $40 million and included a tip that benefited star professional golfer Phil Mickelson.

William "Billy" Walters, who has built a fortune as one of the most successful sports bettors in the United States, pleaded not guilty in federal court in Manhattan to charges of conspiracy, securities fraud and wire fraud. Prosecutors said he faces up to 10 years in prison if convicted.

His arraignment came nearly two weeks after Walters, 69, was arrested in Las Vegas on charges that he traded on insider tips supplied by Thomas Davis, the former chairman of Dean Foods Co., who has pleaded guilty as part of a deal with prosecutors under which he will cooperate in the probe.

Walters had been free on a $1 million bond. But at the hearing, Assistant U.S. Attorney Brooke Cucinella urged a magistrate judge to set bail at $50 million and restrict Walters from using his private airplane, calling him a flight risk.

Walters' lawyer, Barry Berke, argued that Walters needed access to a private airplane to manage dozens of his businesses nationally. But Cucinella said Walters, who has a $200 million net worth, could use the one or possibly two airplanes to flee.

"Those airplanes are flown by pilots on his payroll," Cucinella said.

U.S. Magistrate Judge Andrew Peck rejected the prosecution's arguments, setting the bond at $25 million and allowing Walters to continue using a private airplane, provided the pilots signed on to part of the bond.

"Oh to be rich and not ride in coach, but I do think that's a restriction that's not worth the bother," Peck said.

Prosecutors said from 2008 to 2014, Walters earned profits of $32 million and avoided losses of $11 million trading on inside information about Dean Foods from Davis, and another $1 million trading on a tip about Darden Restaurants Inc.

The U.S. Securities and Exchange Commission in a related lawsuit last month said Mickelson, who has won three Masters golf titles, also at one point bought Dean Foods' stock on a recommendation by Walters, to whom he owed money after placing bets with him.

Mickelson was not accused of wrongdoing, but he reached an agreement with the SEC to pay back $1.03 million the regulator said he earned trading the dairy company's stock.

The case is U.S. v. Davis et al, U.S. District Court, Southern District of New York, No. 16-cr-338.