The head of United Natural Foods' speciality distribution arm is set to retire from the company, the US firm has announced.

Robert Sigel is to leave UNF after serving as president of speciality distribution and president of Millbrook Distribution Services.

Effective from 14 March, Sigel is leaving to pursue other interests. He joined the company following the acquisition of Millbrook in November 2007.

"We'd like to thank Bob for his contributions during the initial integration of Millbrook into UNFI, and we wish him the best in his retirement," said Michael Funk, president and CEO.