IBM laid off 1,315 US workers from its global services division, according to a union group under the Communications Workers of America.
The world's largest technology company also released an unknown number of contractors, and job cuts will continue, Alliance@IBM said on its website.
An IBM spokesperson could not immediately be reached for confirmation.
The company said at an investors' conference last month that it would reduce costs in the US and noted a slowdown in its US enterprise business. IBM reported its net profit rose 8 percent year-over-year in the first quarter to $1.8bn.
The layoffs come just a day after IBM announced plans to open a new call centre in Daleville, Indiana that will eventually create 500 jobs. The IBM call centre investment was reportedly made in return for a 10-year, $1.16 billion contract with Indiana's Family and Social Services Administration.
IBM ended last year with 355,766 employees worldwide, up from 329,373 in 2005, according to its annual report.