Aug. 24 (Bloomberg) -- New York City’s ranks of the unemployed swelled to 402,200 last month, the highest number since July 1992, Comptroller William Thompson said.

The comptroller, in a report on economic issues facing the city, said another 170,000 people worked part-time in the first half of this year who would rather have full-time jobs. That represents a 70 percent increase over last year, he said.

The jobless total, reported by the state Labor Department Aug. 21, and the estimated number of part-time workers who would rather be fully employed, come from a national survey conducted by the U.S. Bureau of Labor Statistics, said James Brown, an economist with the state Labor Department.

“Back in the fall of 2008, I estimated that as many as 250,000 jobs could be lost as a result of this recession, sending the number of unemployed in New York City to more than 400,000,” Thompson said in the report. “Unfortunately, we have passed the 400,000 mark ahead of schedule.”

He said almost 130,000 New Yorkers have been unemployed and searching for work for six months or more.

On Aug. 20, the state Labor Department reported New York City’s unemployment rate rose to 9.6 percent in July from 9.4 percent in June, the highest since June 1997, while the statewide rate fell by 0.1 percentage point to 8.6 percent. The national unemployment rate is 9.4 percent.

The comptroller said he saw no need to revise his prediction that the recession would cost the city about 250,000 jobs.

Thompson, 56, seeks the Democratic nomination to oppose Mayor Michael Bloomberg, 67, who seeks a third term running on the Republican and Independence Party ballot lines.

The mayor is founder and majority owner of Bloomberg News’s parent, Bloomberg LP.

To contact the reporter on this story: Henry Goldman in New York City Hall at hgoldman@bloomberg.net.

Last Updated: August 24, 2009 12:32 EDT