If the merger goes ahead, the combined firm would have 37 offices in 17 countries and employ around 1,300 lawyers. Revenues from the combined operation would top 405m.
It's anticipated partners in both firms will be asked to vote on the merger before the end of 2010.
Squire Sanders chairman James J. Maiwurm and Hammonds managing partner Peter Crossley said preliminary talks had shown that both firms were focused on geographic and practice growth that meets the needs of multinational clients. Large clients want to work with firms that have global depth and breadth, the joint statement added.
Mr Maiwurm said: "While we are still at an early stage, our discussions to date indicate that such a merger would appeal strongly to clients that want high-quality legal services from lawyers who have global experience and who understand and respect client demand for value.
"Hammonds has a well-developed platform that would complement our presence in Europe, would add to our capabilities in Asia and would enhance Squire Sanders' broad-based Latin America resources."
Mr Crossley added: "There is an obvious cultural fit between the two firms." He said Hammonds' long-term strategy included a commitment to establish stronger ties in the US, where the firm has a growing client base.
Hammonds was founded in Bradford in 1887, by Albert Victor Hammond. The firm, which has offices in Leeds and Manchester, now employs more than 1,000 people, including 170 partners, working out of 10 offices in six countries.
Mr Maiwurm added: "We know Hammonds shares the commitment to excellence that we demand of ourselves. But Hammonds, unlike many firms, also shares our understanding that excellence can and should combine with cost-effective, creative legal service."