NEW YORK (CNN/Money) - U.S. businesses in May announced the lowest number of job cuts in a year, but it looks like they might have just been getting warmed up for June.

It's only June 5 and already IBM Corp. has announced 1,500 job cuts, USA Today has reported that WorldCom could announce up to 16,000 layoffs soon, and Hewlett-Packard Co. has set a rapid timetable for its previously announced 15,000 cuts.

WorldCom would not comment on the job cuts.

There were 84,978 job-cut announcements in May, according to a report Tuesday by Chicago-based outplacement firm Challenger Gray & Christmas.

Though it's impossible to know how many job cuts actually will be announced in June, Challenger pointed out Tuesday that May typically is a slow month for announcements. Layoffs soared after a slow May last year to 124,852 announcements in June and 205,000 in July.

The Labor Department is expected to report Friday that the May unemployment rate rose to 6.1 percent from 6.0 percent in April, according to economists surveyed by Briefing.com.

Unemployment typically is a lagging indicator, rising even as the economy recovers because businesses are reluctant to hire new workers until they're sure the recovery is real.