One of the country’s most prominent law firms, Herbert Smith Freehills, is merging with a New York litigation and transactions specialist, adding 100 partners and becoming the first local partnership to have an expansive operation in the United States.

If approved by three-quarters of the partners at both firms in a vote scheduled for February, Kramer Levin Naftalis & Frankel would merge with HSF to become Herbert Smith Freehills Kramer.