The move will see Bond Pearce's Aberdeen office, opened in 2007 and its only base in Scotland, going from two partners to six in 2013.
The highest profile mover is Uisdean Vass, who led the oil and gas team at MMS. Mr Vass is expected to work alongside Bond Pearce's London team to look at international opportunities in the energy sector.
Also moving is offshore wind specialist Richard Cockburn, a member of the Association of International Petroleum Negotiators; corporate lawyer Gordon Hobkirk; and real estate partner Fraser Leslie.
All of them have wide experience of the market in Aberdeenand track records of working with oil and gas businesses.
The north-east of Scotland office is described as an integral part of the growth strategy for the UK-wide energy practice at the business, which has clients including E.ON, Total and RWE npower renewables.
Bond Pearce recently confirmed it would merge with English-focused Dickinson Dees in May next year.
Luke Gabb, head of energy at Bond Pearce, said: "This is a fantastic opportunity to significantly expand our oil and gas expertise with the acquisition of a superb team with an excellent track record and reputation in the marketplace.
"This provides us with an excellent platform for further growth, with many clients engaged in both renewables and oil and gas business.
"Expanding our office in Aberdeen makes great business sense because it is a key location for the oil and gas industry and the wider energy sector, and we will continue to consider other opportunities."
Kenny Paton, oil and gas partner in Aberdeen, said: "This will enable us not only to expand our already extensive oil and gas practice in Aberdeen and continue to grow our Scottish client base but to provide a broad spectrum of legal advice for the firm's existing UK clients with business interests in Scotland."
Chris Smylie, chief executive of MMS, said his firm intends to appoint new staff and has already relocated some of its lawyers to Aberdeen.
He said: "We are well advanced in our plans to reinforce our oil and gas team both in Aberdeen and London. There will, therefore, be no gap in service provision for our Aberdeen clients as a result of these departures.
"I am very clear that in each market we service we need to have the very best lawyers available locally. We are accelerating our plans for recruitment in line with that objective, in addition to relocating some of our own excellent lawyers where appropriate.
"We are absolutely clear about the role and importance of our Aberdeen office and had already been taking steps to add to the high quality service we offer in Aberdeen, to the benefit of our clients in the north-east."
MMS, which recently reported a 10% rise in pre-tax profits to £14.24 million, confirmed David Knox, formerly of Dundas & Wilson, is joining to head up its UK pension law team in January.
That follows on from banking specialist Stuart Fitzsimmons and private client lawyer Alan Eccles being promoted to partner earlier this month.