Victor H. Gotbaum, a shrewd and combative Brooklyn native who headed the nation’s largest municipal employees’ union for two decades and played a pivotal role in saving New York City from bankruptcy in 1975, died on Sunday, the New York Times reported yesterday. As executive director of District Council 37 in New York, Mr. Gotbaum was one of the nation’s most prominent union leaders during a tumultuous time in the history of organized labor. To many in New York, he was simply Mr. Labor, especially in 1975, when he clashed and then compromised with bankers, state officials and Mayor Abraham D. Beame in an effort to keep the city afloat. That year, New York came perilously close to defaulting on its debt when several big banks threatened to close off credit unless Mayor Beame took draconian steps to cut the budget. The mayor soon called for eliminating 38,000 city jobs and denying municipal workers a planned 6 percent raise.