Experience of two bruising merger bids in private practice proved a useful primer for James Retallack when he joined the board of takeover target Aggregate Industries, finds Caroline Hill

Aggregate Industries' (AI's) former legal and compliance director James Retallack knows a thing or two about mergers. In the glare of the public eye he guided Birmingham and London law firm Edge Ellison through the rocky aftermath of dramatically collapsed merger talks with then Pinsent Curtis (now Pinsent Masons) in 1997 and, after an oft-challenging three years, into a union with legacy Hammond Suddards. Only four years later, at major heavy building materials company AI, he was part of the board guiding the FTSE 250 company through a £1.8bn merger with Swiss-founded aggregate and cement giant Holcim.

A well-connected and personable employment lawyer, Retallack is best known for his baptism of fire as senior partner of Edge Ellison in 1998, and his recollections of the abandoned Pinsents merger bid are enough to send chills down the spine of any partner in a management role. Edge had gone as far as to notify its partners of the impending union when, one Sunday, Retallack recalls, he woke up to find the details of the merger in the national press. By 4pm that afternoon, the deal was off.

Retallack describes the immediately ensuing period as a "tailspin". Edge staff knew that Pinsents was seen as stronger and more successful and that the alleged merger was, therefore, a takeover. The inevitable trickle of departures began.

It was Retallack who put forward a then much publicised three-year plan, 'The Way Forward', which stressed that the firm needed to build on its successful Birmingham office, introduce a more democratic management and remuneration structure and focus on international development. When incumbent senior partner Digby Jones handed in his notice in the spring of 1998, Retallack says: "They said, 'You think you can do it boy, you'd better do it.'"

As newly-promoted senior partner, Retallack famously engineered a public no merger period as well as an almost unprecedented three-year lock-in agreement with the firm's partners.

It was in 2000, as Edge was fast approaching the end of its three-year plan, that Hammonds was fortuitously looking for a way to boost its London offering. Hammonds was also a national law firm but didn't have a Birmingham presence. The rest is history.

The united firm initially became known as Hammond Suddards Edge, but there was never any doubt that it was a takeover, and in 2002 'Edge' was dropped as part of a rebranding exercise. However, Retallack is adamant that there is no shame in being taken over. "We were not big enough or strong enough to carry on as an independent firm. We could either acquire or be acquired, and we were acquired by Hammonds," he observes matter-of-factly.

Then senior partner of the united firms' Birmingham office and with plans to return to life as an employment partner, Retallack was approached by AI's departing human resources director and asked if he would take over the role. "I said, 'you've caught me at the only time in my life when I would consider it' – three months earlier and I would have been doing the merger and three months later I would have got back into practice. I've always been a believer in fate and sometimes you have to be in the right place at the right time. That's where I was with AI."

The role presented Retallack with a new challenge and one not without risk. "I knew if I wanted to I could continue being an employment lawyer for the next 20 years or I could gamble and join the board of a public company – which was very much a takeover target and I could be out of a job in a year but see life from a new perspective and have experiences I would never have as an employment lawyer."

Retallack dived into the role of group resources director, but with Holcim's 2005 offer for AI, it seemed his mettle was truly to be put to the test. "I was having lunch in Birmingham when the chief executive called and said, 'Can you get on a train, Holcim's made a bid.' I got on a train with an overnight bag and came back two weeks later."

With good reason, Retallack cites the merger as the most significant challenge he faced while working for AI, charged as he was with co-ordinating the due diligence on a deal led by former Freshfields Bruckhaus Deringer corporate partner James Davis – now a non-executive director of AI – and for Holcim by Slaughter and May corporate rainmaker William Underhill. Retallack says: "Both were absolutely excellent. To be on the receiving end of a bid and manage the due diligence was a brilliant experience."

Brilliant or not, the development did mean that Retallack assumed he was out of a job. "I thought, these guys won't want me. They said in a meeting, 'We want AI because of its management, so we're not getting rid of anyone', but I didn't believe it – I thought, you would say that, wouldn't you. But six years later I was still there."

An internal reorganisation in 2008 saw Retallack's resources role largely subsumed by the chief executive and he returned to legal work in the form of AI's legal and compliance director, in the process cutting the legal spend from £2m at its height in 2007 to around £1m by bringing much of the work in-house.

However, the move prompted Retallack to consider his future. "At the end of the day, in 2001 if AI had said, 'Leave Hammonds and come and be our in-house lawyer' I would have said no. The whole attraction was to do something different."

Once again, Retallack found himself improvising, this time writing himself out of AI's legal department, which has grown incrementally over the past year to a team of seven, including new legal director James Atherton-Ham, formerly McGrigors London director of energy and utilities.

Mission complete and without a merger to completely absorb him, Retallack is stretching his time between a number of different projects, including being a frontman for professional network Nexus and working two days a week with his former team at Squire Sanders Hammonds.

"There simply aren't enough days in the week, that's the problem," he says.