New York’s most powerful restaurant marriage has come to an end.

The chef Daniel Humm and his business partner, Will Guidara, who in 2011 bought the elegant restaurant Eleven Madison Park from their mentor, the restaurateur Danny Meyer, and transformed it into one of the world’s most lauded dining destinations and the crown jewel of a restaurant group that stretches from London to Los Angeles, are splitting up their multimillion-dollar partnership.

With help from an investor, Mr. Humm is buying out Mr. Guidara’s share of the business. Mr. Guidara plans to use the money to open his own restaurant group. Neither would disclose the financial terms of the deal.

Although some top staff members of the group had known about the pending breakup for weeks, most of the staff of about 1,000 people found out today in an email.

“It’s been an incredible run and I think we both learned a lot from each other, but we also have evolved in different ways,” Mr. Humm said in a joint interview with Mr. Guidara. “We’re extremely proud. We just came to the conclusion in the end that what would be best for the company is if I continue to run it.”