Members of Office and Professional Employees International Union Local 212 voted overwhelmingly to merge with a New York City-based sister union, Local 153.

Buffalo-based Local 212 has about 500 members and represents office and clerical workers at nine area employers, including Blue Cross/Blue Shield of Western New York.

Local 153 represents 16,000 workers at employers including the New York Stock Exchange, Emblem Health, Yankee Stadium and the Archdiocese of New York.

Caroline Muszynski, Local 212’s president, said the merger will give Local 212 members additional clout and new benefits and services. The vote to merge was 240 in favor and four against.