First Lovells and now Denton Wilde Sapte. Two of the former “chasing pack” London law firms that were, a decade ago, attempting to challenge the magic circle for premium instruction have joined forces with two sprawling US national firms (Hogan & Hartson and Sonnenschein Nath & Rosenthal respectively).

Lovells spread its international network to France and Germany via mergers (with Simeon & Associes and Boesebeck Droste) and stand-alone launched in places such as Italy and Spain as well as Central and Eastern Europe and Asia. There have been teething problems of course. Senior defections, office closures and mixed fortunes in cracking these markets.

Dentons has been more restrained, preferring to focus on the Middle East and Africa. The firm even pulled the plug on its Asia network in 2003 although has previously courted US practices, notably Pillsbury Winthrop.

Both UK firms have their strengths of course, especially in finance, projects and energy. But it would seem the ambition to conquer the world had fizzled out as time went on. Indeed, magic circle firms have also scaled back their international exposure but maintain modest teams that focus on premium M&A and banking transactions.

The decision of Lovells and Dentons to tie-up with US firms shows that both believe big is better. Having a US hub – where litigation remains a major engine and clients are aplenty – provides much needed support and referral opportunities. Neither Hogan nor Sonnenschein are top-tier New York firms so their emphasis is on a wider practice offering, which should also benefit the full-service model of Lovells and Dentons.

Transatlantic consolidation is not a new concept. US firms such as K&L Gates, Jones Day and Reed Smith have picked off smaller London practices in a bid to enhance their UK presence. Mergers between big US and big City firms have been, however, a rarer commodity (DLA Piper is something of a unique beast).

So is this the start of a new wave of transatlantic consolidation? SJ Berwin has been skirting around a US suitor (first Orrick Herrington & Sutcliffe and then Proskauer Rose) and other respected firms that have not quite managed to build the international network they aspired to and face challenges in light of the recession. The main “chasing pack” candidates left are Simmons & Simmons, Norton Rose and Ashurst. All have their strengths and weaknesses but all three could be an attractive target if ambitious US firms, such as Orrick or Bingham McCutchen, decided to take the plunge.

A big part of the chasing pack’s problem has been differentiating themselves from each other. Teaming up with a US firm can help carve out a new identity for these practices. Two of the UK’s top 20 law firms have now teamed up with US firms in 2010 with SJ Berwin also signalling its intent to look stateside. After years of anticipation, the dawn of transatlantic consolidation could finally be on the horizon.