Hyped it may be, but the gospel of Maher and Greenberg could win some converts

"Everyone likes to argue about the intangible value that they contribute. But I say, 'If you want to be rewarded for intangible value, then here's a hug – that's intangible.'" Cesar Alvarez, chief executive, Greenberg Traurig.

That quote, contained in a 2007 profile by our sister title The American Lawyer, goes a fair way towards summing up the US law firm that has just recruited Paul Maher for a flashy London launch. Driven, focused on the bottom-line, hard-nosed even – if the mandate from Maher to his agents at Shilton Sharpe Quarry (SSQ) was, "Get me the polar opposite of my old firm," it's definitely mission accomplished, as an employer further from the cultural history of the patrician Mayer Brown is hard to imagine.

Where Mayer Brown was, initially at least, a union of a good-but-sleepy London firm with a good-but-sleepy US law firm with too much regard for its own status, the Florida-based Greenberg exudes entrepreneurialism and drive unencumbered by self-image or the weight of tradition. The closest UK comparison would probably be Hammonds in its mid-1990s heyday (on balance, that's a compliment). This is a firm, by all accounts, that puts far more stock in getting on with what it wants to achieve than worrying about what 'the market' says it should be content with achieving. The result has been one of the fastest growing law firms the US, achieving revenues in 2008 of $1.204bn (£752.5m) and average partner profits of $1.31m (£818,000). That expansion has been backed by one of the most sustained and aggressive campaigns of lateral hiring ever seen in global legal services, overseen by a lean, powerful and fast-moving management team ready to spend big for those that deliver big. Until now that firm has been largely restricted its ambitions to the US. Until now…

Which brings us to Maher's decision to launch a City practice for the US firm under the name Greenberg Traurig Maher (GTM) along with two fellow Mayer Brown partners. You certainly have to admire the man's guts in going from senior management to take on a project that will rise and fall largely on his own contribution at ground level. But assessing GTM's potential does mean dealing with the sizeable baggage Maher has accumulated over his career. He remains, due to his impatience and sometimes spiky personality, a divisive figure. Yet most neutral observers saw him as Mayer Brown's top corporate lawyer in the UK with an unusually strong client following for a lawyer in senior management. He also possesses common sense and sound commercial instincts and the ability to inspire those he doesn't irritate.

For some disciples, that praise isn't celebratory enough – to listen to the more hyperbolic claims made of Maher, you may think this corporate lawyer walks on water. But, despite his undoubted ability, there are better corporate lawyers in the Square Mile. And some agnostics may even wonder, if Maher is such an unparalleled M&A superstar, why there was not more visible progress at Mayer Brown's UK corporate team in the first five years after the Rowe & Maw union.

Nevertheless, the Maher/Greenberg union may deserve its high billing, even if only for attempting to do something fresh in the City (or rather trying to make good on what US firms promised a decade ago and then largely failed to deliver). The mission, which is expected to see aggressive expansion in the UK and abroad over the next 12 months, is audacious and factors in GTM recruiting a clutch of heavy-hitters at partner level. Though GTM is hunting for some junior partners as it aims to rapidly reach full service, it's clear that they are not aiming to stock the practice with water-carriers for Maher. The theory is that the sizeable pool of quality but unsettled partners at UK firms and US firms' City arms will be attracted to a start-up that is long on ambition and short on committees. If that theory proves sound then the firm can go to clients with a lean, all-star team that should be able to deliver quality at a price top firms will struggle to match, a hope underlined by Maher's aim of shaking up the legal services business model. Maher says he wants to respond to a "paradigm shift" in client expectations, adding: "I want to take another look at client service. We want to be more client-focused, working through teams, not practices." Perhaps Gavin Sharpe of SSQ puts it more snappily: "This is about going to Merrill Lynch and saying, 'You've never heard of us but we've got your dream team and we will deliver better value.'"

Maher and co are certainly preaching a strong message. If Greenberg is willing to back it up with the level of investment that is being talked about – and despite the US firm's reputation for expecting new offices to be profitable very quickly, Maher is adamant that it is – then the ranks of the faithful look set to swell. That would only be the first step on a long and winding road, but it would be significant nonetheless.