Simon Pilling is joining forces with John Laithwaite, who is one of his long-standing clients.
Mr Laithwaite was the driving force behind the development of Yorkshire-based JLA, the UK’s largest commercial laundry equipment supplier.
In March 2010, it was announced that private equity firm HG Capital had taken a majority stake in JLA, which is based in Ripponden, West Yorkshire.
In a note sent to friends and clients, Mr Pilling said that, after more than 12 years as a partner at Addleshaw Goddard, he had decided to pursue an opportunity to work with a client.
His note described it as a “once in a lifetime” opportunity to do something totally different from law.
An Addleshaw Goddard spokesman said: “Simon will be leaving the partnership later this Summer to work with John.
“Simon has made an important contribution both professionally and personally to our business and he leaves with our very best wishes.
“The Leeds team led by Yunus Seedat, Neil Woolhouse and Garry Elliott have had a phenomenal period where they have worked on some of the largest deals in the region, such as Card Factory, JLA, Andrew Page, Republic, Go Outdoors, UK Wealth Management, and outside the region.
“It goes without saying that we’re committed to continuing to expand the team in Leeds and are determined to build on what has been a great period.”
Mr Seedat said Addleshaw Goddard had a strong pipeline of clients and transactions.
According to information stored at Companies House, Mr Laithwaite, of Halifax, resigned as a director of JLA in March 2010.
He became a director of Aghoco Ltd, a real estate investment firm, in June 2010 and a director of Visual Energy Ltd in January 2011.
He is sole director of both companies, which are registered at his home address.
According to its website, Visual Energy offers laundry distributors the chance to increase profits using a product that improves the energy consumption of heating and water systems.
Mr Laithwaite was unavailable for comment yesterday.