Former Alsop Wilkinson partners are bracing themselves to work in open-plan offices when Dibb Lupton Alsop's Manchester staff move into one of the two new city centre Great Bridgewater blocks.

The move coincides with Addleshaw Booth & Co's and Masons' relocation to the block next door. Donns is also moving, from Cross Street, its home of nearly 30 years, to one floor of a newly built block at 201 Deansgate.

Paul Nicholls, Dibbs' Manchester managing partner, said Dibbs on Albert Square had been planning to move to Great Bridgewater on Lower Mosely Street even before its merger with Alsop Wilkinson.

The firm's 200 Manchester employees will take over three open-plan floors (38,500sqft) in the block when they move in August – a change for former Alsop partners who are used to having their own offices.

Price Waterhouse will be in the remainder of Dibbs' block. The newly-merged Addleshaw Booth & Co will move its staff from two existing offices into the block next door, along with Ernst & Young.

E&Y has sublet one floor (18,000sqft) to Masons. The firm's 65 Manchester staff will be moving from Exchange Quay, Salford, in August.

“We were made an offer we couldn't refuse,” said Michael Stephenson, Masons' director of office services. “We had an option to break our existing lease, so we exercised it.” He said he expected staff numbers to increase to 75 by the end of the year.

The firm is also relocating its Leeds office in May next year, from Minerva House, East Parade, to take up one floor of the city centre Springfield House.

Seven-partner firm Donns has signed a 15-year lease on one floor (15,000sqft) of the newly-built city centre block at 201 Deansgate.

Its 150 staff will move in July from the building on Cross Street where the firm was founded 28 years ago. Donns auditors Deloitte & Touche are also moving into the building.