The number of planned layoffs at U.S. firms fell modestly in July, though the healthcare and defense sectors saw the biggest job cuts, a report on Thursday showed.

Employers announced 37,701 layoffs last month, down 4.2 percent from 39,372 in June, according to the report from consultants Challenger, Gray & Christmas, Inc.

Still, July's job cuts were up 2.3 percent from the same time a year ago. For 2013 so far, employers have announced 296,633 job losses, down from the 319,946 that were seen in the first seven months of last year.

At the current pace, layoffs for 2013 could be below 2012's total of 523,362, which was the lowest level since 1997.

The healthcare sector saw the biggest layoffs, cutting 6,843 employees, the largest monthly amount for the sector since November 2009.

The aerospace and defense sector came in second, letting 4,889 workers go. Fewer than 1,000 of last month's layoffs were attributed to the across-the-board government spending cuts known as the sequester, the report said.

The figures come a day ahead of the key U.S. jobs report, which is forecast to show the economy added 184,000 jobs in July, enough to push the unemployment rate down to 7.5 percent.