Societe Generale, France's third-biggest listed bank, and US investment management company Alliance Bernstein plan to form a joint venture focusing on global cash equities and equity research.
SocGen plans to take a 51% interest in the venture, for an undisclosed sum, with an option to take 100% ownership after five years.
The French bank, which expects to close the deal before the end of 2023, said the business would boost its profits from 2025 onwards.
In a statement, Slawomir Krupa, the head of SocGen's investment bank said: "This partnership with one of the most recognised firms in research and cash equities, combined with our global leadership in equity derivatives, would create an undisputed leader across the equity business for the benefit of our issuer and investor clients.”
The move is part of SocGen's push to diversify its investment bank away from its reliance on its leading equity derivatives franchise.
The equities sector is also a focus for large French banks, with rival BNP Paribas taking over its equities joint venture with Exane last year.
"Bernstein's research and SocGen's equity capital markets, derivatives and prime capabilities offer good complementarity, which would allow for more scale, a wider range of services and some more synergies, increasing the profitability of this business," said analysts at brokerage Jefferies, which has a 'buy' rating on SocGen shares.