Jobless Americans had a much harder time finding work in the fourth quarter of 2001 than they did in the same period a year earlier, a government report showed on Wednesday.

The number of workers laid off from U.S. firms who remained unemployed for more than 30 days jumped to 486,406 in the fourth quarter, compared with 427,070 in the October-December 2000 period, the Bureau of Labor Statistics said.

The near-14 percent rise represents the fifth consecutive quarterly increase in what the Labor Department calls "extended layoffs" - job cuts leading to unemployment for one month or more.

The manufacturing sector accounted for 35 percent of extended layoffs in fourth quarter of 2001, while 9 percent of those who stayed jobless for a month or more in that period worked in the services sector, the report said.

The Sept. 11 attacks had a considerable adverse effect on the nation's already shaky labor market, the report said, with 33 states reporting extended layoffs "related in some way to the September 11 incidents."

Reports for the weeks ended Sept. 15 through Dec. 29 show layoffs involving 114,711 workers can be directly or indirectly attributed to the attacks, the BLS said.

Layoffs attributed indirectly to Sept. 11 include those in firms and industries not located in the immediate vicinity of New York's World Trade Center, but nevertheless sharply affected by the attacks, such as airlines and hotels.