Sonnenschein Nath & Rosenthal LLP and London-based Denton Wilde Sapte LLP have agreed to merge, pending a partnership vote June 9.

Chicago-based Sonnenschein is one of the largest law firms in St. Louis with 750 lawyers, including more than 40 locally.

The merger won’t affect the firm’s operations in St. Louis, according to a Sonnenschein spokesman.

Following the partnership vote, the combined firm will be rebranded SNR Denton, effective Sept. 30. SNR Denton will have about 1,400 attorneys working out of 33 offices in 18 countries. Its two largest offices will be London and New York.

Sonnenschein Chairman Elliott Portnoy will serve as co-CEO of the merged firm alongside Denton’s Chief Executive Howard Morris.

Denton specializes in financial legal advising and represents banks, funds and financial institutions, along with clients in energy and transportation, real estate, technology, media and telecommunications.

Sonnenschein specializes in capital markets, energy, public policy and government regulations, real estate and hospitality, and political intelligence.