Opus chef-director David Colcombe has left the city centre restaurant group.
Mr Colcombe has worked alongside fellow directors Ann Tonks and Irene Allen since its launch a decade ago and built the business up into a popular group with both the business community and city in general.
The company owns the Opus at Cornwall Street restaurant, Café Opus in the Ikon gallery in Brindleyplace and last November launched its third venture, Bar Opus in the ground floor of One Snowhill.
His sudden departure has come as a major surprise and he would only say: "I have left Opus in mutual agreement and I will go on to pursue other interests."
A spokesman for Opus said: "David has moved on to do other things. He has left by mutual agreement."
Appointed an Honorary Fellow and Visiting Professor of Culinary Arts at UCB in 2009, Mr Colcombe is one of Birmingham's most highly-regarded chefs and is a stalwart of the local culinary scene, championing brilliant produce and classical cooking techniques.
His culinary career began after he did a catering course at Solihull Technical College when he was 16.
He said in a previous interview: "When I finished I decided to work in London as Birmingham's food scene was nothing like it is now.
"In those days, hotels were the places renowned for the best food and I sent off about 100 letters, ending up with an apprenticeship at The Dorchester under Anton Mosimann who taught me everything I know about classical cooking.
"He had a brigade of 98 chefs and everything was done in-house - butchery, fishmongery, baking, everything from scratch.
"I started as a fourth commis - there's no such position any more but it was a good way of paying you nothing but you learned so much."
Among his career highlights so far has been cooking for eight world leaders at the G8 Summit in 1998 at the old Swallow Hotel which was taken over by President Clinton and his entourage for the whole summit.
He added: "At Opus, we've had everyone from the Governor of the Bank of England to comedians David Walliams and Matt Lucas."