London firm Radcliffes and Manchester firm Cobbetts have joined the US-headquartered State Capital Law Firm Group.
For Radcliffes, the move comes just two months after it pulled out of the Commercial Law Affiliates (CLA).
The move is good news for the firm, which left the 200-member CLA in January, six months after the group admitted Hammond Suddards.
Sources close to the CLA said Radcliffes' departure was prompted by Hammonds' insistence on being the only English member firm, although this was denied by both the firms and the CLA.
Formed in 1989, the State Capital Group consists of more than 100 independent firms.
The entry of Radcliffes and Cobbetts was approved at a meeting held in Denver earlier this month.
Among the better-known firms in the network are Connecticut firm Robinson & Cole and Ohio firm Kegler Brown Hill & Ritter.
Radcliffes and Cobbetts will not, be the only UK firms as Wragge & Co and Mills & Reeve are members.
The presence of Wragges and Mills & Reeve is explained by the fact that the State Capital group historically had connections with the Norton Rose M5 group, the UK network of which the two firms were members until it disbanded in August 1998.
Legal Week understands that the State Capital group, which was formed to handle regulatory work, is evolving in the US because capitals are often not the main commercial centre in a state.
Since 1996, 50 international firms have joined the group. European member firms include Germany's Wessing & Berenberg-Gossler, Spain's Castro Sueiro & Varela and the Netherlands' Houthoff Buruma.
Philip Peacock, the Radcliffes corporate partner behind the link-up, said: "We were invited to join and were very interested in doing so at an important stage in the firm's development.
"The invitation was very timely."
Cobbetts senior partner Stephen Wite said: "We are delighted to be a member of the State Capital Law Firm Group. This will enable us to establish relationships with firms throughout the world."