Mayor Michael R. Bloomberg asked attorneys at the New York State Bar Association’s annual meeting yesterday to support changes to tort laws that he said could save the city tens or hundreds of millions of dollars a year in medical malpractice and liability awards.

Mr. Bloomberg, addressing several hundred state bar members at the group’s “presidential summit,” likened civil litigation against New York City to a “lottery” where a “teeny fraction” of litigants reap huge awards while the vast majority get nothing. He said that while the city paid about $20 million in awards in 1978, it now pays out just under $500 million annually to civil litigants.