Magnus Swanson, chief executive of MMS, told The Scotsman, that 38 posts were being made redundant, out of a total headcount of 579.
He said the job cuts followed a series of measures designed to avoid redundancies, including seconding staff to clients and transferring lawyers to other areas of the practice.
MMS – which has offices in Edinburgh, Glasgow, London and Aberdeen – said the staff affected would receive an "enhanced" redundancy package, including support in finding future work.
Swanson said: "This has been an extremely difficult decision to take. We value our employees highly and have implemented a number of measures to ensure we minimise the number of job losses.
"These measures include seizing opportunities to second lawyers to clients, redeploying staff to busier areas and offering prospective trainees a package to defer their start date.
"However, given the economic environment in which we operate, further action was necessary.
"We aim to ensure our business is in the correct shape to service the needs of our clients as we anticipate they will evolve in the next two to three years."
News of the job losses at MMS comes after the axe fell at rivals Dundas & Wilson and Shepherd & Wedderburn. In February, D&W said it was shedding up to 50 of its 669 posts, with Shepherd & Wedderburn making 14 staff redundant. Brodies axed up to ten posts, while Burness shed up to 19.