Squire Sanders is in preliminary merger discussions with Washington-based public policy and lobbying firm Patton Boggs.

In a statement, the two firms said discussions are in the early stages, and that there was no assurance a combination would be completed.

If the pair were to tie-up, it would create a 1700-lawyer firm in 45 offices across 22 countries, with combined revenues of more than $1bn (£600m).

Squire Sanders, which is structured as a Swiss verein, combined with legacy UK firm Hammonds on 1 January 2011, and counts 39 offices across 19 countries.

The firm underwent a period of major expansion in the Asia-Pacific region in 2012, adding offices in Singapore, Seoul and Sydney.

Though the firm has a global board, it operates separate management committees in the UK and US. Last October, it re-appointed London-based litigator Peter Crossley as European managing partner alongside New York and Cincinnati-based corporate partner Stephen Mahon.

Patton Boggs, meanwhile, has a much smaller footprint, with around 360 lawyers spread across five US and four Middle East offices. Earlier this year, the firm announced it was closing its New Jersey base, amid a 12% drop in revenue for 2013 and rapidly contracting lawyer numbers.

According to the American Lawyer, the firm had 485 lawyers at the end of 2012, meaning headcount has dropped by more than a fifth in a little over a year.

Currently, both firms have offices in New York, Washington DC and Riyadh. Were a deal to go ahead, it seems likely Patton Boggs lawyers would be absorbed into Squire Sanders' partnership, rather than form a separate verein under the joint-firm brand.