LOS ANGELES—The billionaire investor Carl C. Icahn is going to have an even greater say in Herbalife, Ltd., the marketer of nutrition and weight-management products.   

Herbalife today announced an agreement to nominate three representatives affiliated with Icahn to join its board of directors, Hunter C. Gary, Jesse A. Lynn and James L. Nelson. Icahn, whose entities own 16.8 percent of Herbalife's outstanding shares, already has two representatives on Herbalife's board: Jonathan Christodoro and Keith Cozza.

If Gary, Lynn and Nelson are elected, 38 percent of Herbalife's board will represent Icahn entities.

Herbalife said its board will remain at 13 members because two board members, Carole Black (former president and CEO of Lifetime Entertainment Services) and Michael Levitt (chairman and CEO of Stone Tower Capital LLC) are nearing the end of their three-year terms while another board member, Colombe Nicholas (a consultant to Financo Global Consulting), intends to resign.

Herbalife plans to nominate the Icahn representatives during its shareholders meeting on April 29. Icahn has the right to increase his ownership stake in Herbalife to 25 percent of the company's outstanding shares, according to Herbalife.

Icahn has defended Herbalife against allegations from another well-heeled investor, Bill Ackman, who claims the multi-level marketing company is an illegitimate pyramid scheme and has bet $1 billion against Herbalife.

"We remain resolute in our commitment to the long term success of Herbalife," Icahn said in a statement. "We continue to have confidence in its board and management team, and believe in the company's great potential.

Until just a few weeks ago, Ackman's bet against Herbalife's shares (NYSE: HLF) was a bust incurring hundreds of millions of dollars in paper losses because Herbalife's stock price had been going in the opposite direction than the activist investor had predicted: up. Over the last 52 weeks, the stock price peaked at $83.51 on Jan. 8, 2014.

Ackman's paper losses began to shrink when the FTC confirmed on March 12, 2014 that it had launched an investigation into Herbalife, issuing a civil investigative demand.

According to a March 21 article in Bloomberg News, Ackman was close to breaking even on his wager.

Shares of Herbalife were up this afternoon roughly 8 percent to $53.39. On March 11, before the FTC probe was revealed, Herbalife's shares closed at $65.39.