Northern Foods is to move its head office from Hull to Leeds, ending a 60 year connection with the city.
About 100 people are employed at the building in St Stephen's Square which is scheduled for redevelopment.
A spokesman said it was hoped all the head office staff would be able to move to the new offices near junction 46 of the M1 in east Leeds.
Part of the reason for the move is to be nearer Northern Foods' administrative offices in Wakefield.
The spokesman added that the company now operates out of 40 sites in the UK and the new head office would be "much closer to the heart of the business."
Northern Foods supplies chilled and convenience foods to all the leading UK supermarkets.
It is hoped the head office will move to Leeds early in 2005.
The Cavaghan and Gray subsidiary which employs 300 people at Bright Street in Hull is not affected.