NEW YORK (AP) -- A long-simmering spat between billionaire investors Carl Icahn and Bill Ackman boiled over into a shouting match on live television Friday.

The two Wall Street titans, interviewed by phone simultaneously on CNBC, traded barbs about an old investment deal and on Ackman's position in the nutritional supplements distributor Herbalife (NYSE:HLF).

Ackman was being interviewed by CNBC host Scott Wapner a day after Icahn made disparaging comments about him on Bloomberg Television. After Ackman had spoken about some of his current investment positions, Wapner interrupted the conversation to say that Icahn had called in and had a few points to make.

"I've really sort of had it with this guy Ackman," Icahn told CNBC. "He's like the crybaby in the school yard."

The two men then spent the best part of thirty minutes telling Wapner why they didn't much care for each other.

"This is not an honest guy, this is not a guy who keeps his word," Ackman said. "This is a guy who takes advantage of little people."

The animosity between the two men dates back to at least 2003, when Icahn bought a stake in Hallwood Realty Partners from Icahn's former fund Gotham Partners. Icahn paid $80 a share for that investment and, according to Ackman, agreed to pay a portion of any future profit to Ackman's fund.

Icahn referred to the clause as "schmuck insurance," and refused to pay up when Hallwood was acquired a year later for $136 a share, according to Ackman's version of events.

Ackman then sued Icahn on behalf of his investors and won. He says that Icahn then called him, congratulated him on winning his claim and said he wanted to be his friend. Ackman declined the invitation.

"Carl Icahn does not have a good reputation for being a handshake guy," said Ackman.

That version of events, in particular the claim that he wanted to be Ackman's friend, is disputed by Icahn. He also said that he had helped Icahn "out of a jam," when he bought the stake in Hallwood.

"To get the record straight, I never asked Ackman to be my friend," Icahn told CNBC. "Quite to the contrary, Ackman has stated to me on more than one occasion that it's a shame we are not friends because then he could have invested with me."

One of Ackman's recent big bets is on Herbalife.

In December, the hedge fund manager said that the nutritional supplements distributor was a pyramid scheme and that he was taking a short position in the stock. Short-sellers make money when the stock they're betting against declines.

In an interview with Bloomberg Television Thursday, Icahn had said it was no secret that he neither liked nor respected Icahn, in part because he had been too public in his criticism of Herbalife, "getting a room full of people to bad mouth the company."

Icahn refused to comment on whether he held a position in Herbalife, but speculation is rife that he has bought a stake and is betting against his old adversary.

Despite the ongoing fight with his rival, Icahn has reason to be cheerful this week.

Less than five months ago, Icahn decided to go against the grain and make a big investment in the Internet video service Netflix (NASDAQ:NFLX), at a time when most investor were spurning the company.

Icahn bought a stake of almost 10 percent in Netflix for $324 million. That value of that stake has already more than doubled to $814 million after Netflix's stock surged this week, when the company reported an unexpected profit and an influx of 2 million U.S. subscribers to its service.

The Motley Fool recommends Netflix. The Motley Fool owns shares of Netflix and has the following options: Long Jan 2014 $50 Calls on Herbalife Ltd.. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.