Management boards at both firms recommended to their respective partnerships that the two businesses be combined.
The merger, if it wins approval from a partnership vote held early next month, will see the consolidated firm rebrand as SNR Denton.
SNR Denton will adopt a Swiss Verein structure and operate two separate profit pools but will combine Dentons £167.5m revenue with SNR’s $473m (£328m), with expectations that overall income will come to £500m.
Expected to launch at the end of September, SNR Denton will become a global top 25 law firm by size and gift each other with a foothold in London and New York.
Dentons chief executive Howard Morris and SNR chairman Elliott Portnoy will assume the joint role of co-chief executive officers and will lead a merged board of directors.
Dentons’ Martin Kitchen and SNR’s Joseph Andrew will serve as co-chairman of the new firm.
The move is good news for Dentons, which had been hunting for a US partner for some time.
“Neither of us was interested in pursuing a combination just for the sake of increasing head count and offices – this is not about dots on a map. The end goal for both firms was enhancing legal quality and client service, while also creating a strong global platform. Our newly branded firm will achieve all three objectives,” said Morris.
Management at each firm entered into merger talks within the last few months and according to Morris and Portnoy, both Dentons and SNR conducted independent research on the legal market that brought the firms together.
“Our decision to combine was far from serendipitous – we each had strategic reviews that led us to each other,” said Portnoy.
The merged entity will cover 18 countries in four continents and will act for a number of similar clients, such as Royal Bank of Scotland, Barclays and Deutsche Bank.
But the proposal to merge still relies heavily on a 75 per cent approval vote by the partnerships at both firms, which is to take place on 9 June.
Dentons was founded in the 1700s, making it one of the oldest law firms in the City, and has 17 offices worldwide.
SNR, which was established in 1906, has 13 offices and only two outside of the US.
Portnoy said: “This combination is the next step in our vision to create an elite firm.”