Unlike most American firms landing blinking in the City, one problem that Quinn Emanuel Urquhart Oliver & Hedges will not have is standing out. After all, these self-consciously combative trial lawyers extraordinaire manage to stand out in their home town, having grown at staggering speed from their 1986 launch to become a top 100 US practice in just two decades.

But it's far more than startling growth that the Los Angeles-based upstart is known for. It remains one of the very few law firms of any significance to focus exclusively on litigation, a stance that the firm has turned to its advantage by freeing itself from conflicts, both legal and the hassle of having to compete with transactional departments for resources.

The 375-lawyer firm's singular culture, defined to a considerable extent by charismatic founder John Quinn, also marks the firm out. Playing off its LA roots, Quinn has made a virtue of rejecting the buttoned-down law firm image, even by California's laidback standards.

Part of that culture was an aggressive push to win business that saw the firm regularly cold-calling potential clients, a tactic that Quinn maintains to this day (despite what UK lawyers may believe about pushy American firms, this is not the done thing state-side). That attitude is typified by the firm's marketing and website, which lets readers know that this is the firm you call in "when an eight figure verdict simply won't do".

This is part of the whole trial lawyer mentality. While America is obviously not short of litigators, there's still a very small band of firms that specialise in handling cases before judge and jury. Paul Weiss Rifkind Wharton & Garrison, Cravath Swaine & Moore, Kirkland & Ellis, Jones Day and Boies Schiller & Flexner make up a good chunk of that very exclusive club alongside Quinn, but there's not many others. Members of this club would regard most law firms as settlers and risk-managers, not real trial lawyers.

Quinn has also distinguished itself through its unusual recruitment strategy that saw the firm obsessively target the brightest students long before it really had the reputation to justify their employment. Now it's fully stocked with former law review editors from top schools and brings in the calibre of students you would expect to see at Cravath.

Mixing this weird alchemy of quirk, ambition and audacity, Quinn has rapidly established itself as one of America's most prolific litigation teams and go-to counsel for clients including IBM, Shell, Northrop Grumman and General Motors. And aside from the lucrative defence work, the firm is well known for taking aggressive contingency fee positions to fund high stakes claimant litigation – with Quinn once telling journalists that "we like having skin in the game".

Skin has so far proved highly profitable, according to The American Lawyer, whose 2007 financial rankings show Quinn's revenue to have rocketed to $384.5 (£195m), which average equity partner profits had hit $3.01m (£1.52m), making it one of the US's most profitable law firms.

The question now is if London will know what has hit it as the firm last week recruited Kirkland & Ellis restructuring and litigation partner Richard East (pictured above) to launch its UK practice. The move came after one of his East's clients recommended that he meet Quinn's hiring partner, Bill Urquhart. Certainly, Weil Gotshal & Manges didn't see it coming as the New York law firm had already voted on East's arrival before Quinn's famously speedy recruitment process caused a last-minute change of plan (Quinn claims to have only decided to launch in London three weeks ago despite considering the move for more than three years). Though East's CV doesn't at first glance appear to be a perfect match for Quinn, the firm says his experience closely mirrors that of New York partner Susheel Kirpalani, a former Milbank Tweed Hadley & McCloy partner who helped Quinn gain traction with hedge fund clients.

The plan now is to have a credible team to start pursuing high-end litigation in the City, with post-crunch claims targeting banks and accountants clearly high on the agenda.

How this plays out will be fascinating. No America law firm of this breed has tried launching in the City. The litigation-driven Shook Hardy & Bacon was a very different beast at the time of its troubled 2002 takeover of Arnander Irvine & Zeitman, as are class action specialists like Cohen Milstein Hausfeld & Toll that are currently targeting Europe group actions. Obviously, the US version of the global law firm is also very different, having become grudging converts to the corporate-driven model of their UK counterparts.

In this context, the Sullivans and Weils of this world are hybrids and not much like most pure-blood US law firms at all. Either way, Quinn is going to stand out from this crowd.

But even though the firm has made a great success of taking its model into the highly competitive New York market – building a 130-lawyer practice in six years – some of the initial comments regarding the firm's City strategy suggest that it doesn't quite have its head around how litigation works in the UK. This utterly fresh approach could prove to be either a stunning success or a dismal failure and much will depend on the firm's ability to replicate its famed knack of hiring the best that propelled its growth in the US.

Urquhart, in town "on a quest for the best and brightest the UK has to offer", certainly promises that the firm will live up to its legend in the Square Mile: "We can provide lawyers with a unique opportunity. We still make up partners. We make up lots of them. We make more money than most of our competitors. We have more fun. We have a track record of success where ever we go. We think we will find some UK lawyers with a sense of adventure."

I think so too.