Alastair Mordaunt tells Alex Aldridge why he has no regrets about leaving Freshfields for the OFT – and how a stint in the public sector can do wonders for your CV

As you approach Fleetbank House, home of the Office of Fair Trading (OFT), you can see the offices of Freshfields Bruckhaus Deringer through the mass of buildings clustered just off Fleet Street. The close proximity of the two organisations means that OFT director of mergers Alastair Mordaunt has suffered minimal disruption to his commute since moving from the magic circle law firm in 2007.

That is pretty much where the similarities between life at Freshfields and the OFT end, though, says Mordaunt, who will shortly take up a new position as director of the OFT's markets and projects group.

"It is very different, most obviously on a physical level," he observes, gesturing to the meeting room – notably lacking the corporate trappings you would find at a major law firm. "But the upside is that you get a lot of responsibility when you come into the public sector from private practice. As a senior associate at Freshfields I was responsible for managing perhaps a handful of people on a merger or cartel investigation. But here I have become accustomed to working with much larger groups – plus working with a greater range of people."

Alongside its many career civil servants, the OFT, which is currently looking to recruit a replacement director of mergers, employs 14 barristers, 68 solicitors and 40 economists. According to Mordaunt, the 30-strong mergers team has a similar split between lawyers and economists.

"The other major distinction with private practice is that I handle many more cases here," adds Mordaunt, "which inevitably leads to a more macro-style of working. I have become much better at identifying the core issues in a case and having the confidence to put the things that are not going to raise an issue to one side."

Of the 90 mergers that the OFT director of mergers would oversee in a typical year, many are high profile – and during the last few months have included those between brewers Anheuser-Busch and InBev, supermarket chains Co-op and Somerfield and, of course, the Lloyds TSB and HBOS merger.

Mordaunt says the latter represented the highlight of his time at the OFT to date.

"There was obviously pressure – not least because we had to do our investigation in five weeks rather than the usual eight, and it was much larger than a normal case so there was much more to do. But it meant there was a lot of satisfaction in completing the job as required," he recalls.

Having done all that, though, the Government intervened in the case, deciding that public interest considerations in favour of the merger trumped the competition concerns Mordaunt and his colleagues had identified.

"The general perception of Lloyds HBOS is that the merger regime was effectively put to one side," says Mordaunt, "but our take on the situation was that it was an example of the system working nicely. Everything was extremely transparent, with our report published at the same time as the Financial Services Authority, Bank of England and Treasury reports, and the Minister's reasons then published explaining why he felt public interest considerations were more important. So it remained a democratic process."

The dealings with senior politicians sound glamorous, but, as Mordaunt sips his instant coffee from a paper cup, he concedes that life at the OFT has its downsides.

"It is common for people coming here from private practice to take some level of pay cut," he says. "And I admit my family and I had to slightly change the way we went about doing things as a result of my moving here, but it was not an obstacle for me. If it had been, I would not be doing it and, of course, I am still earning a very good wage by most standards."

Mordaunt believes that the senior associate stage is probably the ideal time for City lawyers who want to move to the regulator because "once you get any more senior, I expect salary would be even more of an issue – and at a more junior stage you may not have enough experience."

The thinking of many who make similar moves to Mordaunt is that a few years in the public sector will boost their CVs to a point where they can secure a higher level return to private practice – a mindset that the OFT is keen to encourage, following the example of the US, where the well-oiled revolving door between law firms and the Federal Trade Commission and Department of Justice antitrust division has proved beneficial for all concerned.

And a stint with the OFT is also something that UK law firms seem increasingly keen on. "Doing a senior public sector role would obviously give an up-and-coming lawyer some excellent experience and make them more marketable," agrees one competition partner at Freshfields.

It worked for Mordaunt's two predecessors in the director of mergers position, Simon Pritchard and, before him, Simon Priddis – with Pritchard securing a partner role with Allen & Overy upon completion of his term two years ago, and Priddis doing likewise at Freshfields. However, as he gears up for his new role within the OFT, Mordaunt seems happy where he is right now.