Sonnenschein Nath and Rosenthal, LLP and London-based Denton Wilde Sapte,LLP have decided to become one, pending a partnership vote June 9.

Chicago-based Sonnenschein is one of the biggest law firms in St. Louis with more than 45 of its 670 total lawyers being based in St. Louis.According to a Sonnenschein spokesman, the merger won’t affect the firm’s functioning in St. Louis.

Following the partnership vote, the joint firm will be rebranded SNR Denton, beginning Sept. 30. SNR Denton will have around 1,400 attorneys functioning in 33 offices in 18 countries. Its two major offices will be London as well as New York.

Sonnenschein Chairman Elliott Portnoy will be the co-CEO of the combined firm along with Denton’s Chief Executive Howard Morris.Denton focuses in monetary legal advising and represents banks, funds and financial institutions, together with clients in energy and transportation, real estate, technology, media as well as telecommunications.

Sonnenschein focuses in capital markets, energy, public policy and government policies , property and hospitality,as well as political intelligence.