General Motors is planning to layoff at least 4,000 salaried workers in North America starting Monday ahead of the company's fourth-quarter earnings report, according to two people briefed on the matter.

The reductions come as the largest U.S. automaker undergoes a massive restructuring announced by CEO Mary Barra in November. GM is halting production at five plants in North America and cutting 14,000 jobs as it realigns its workforce and plants to produce more electric vehicles.

Company executives want to complete as many of the layoffs as possible before the company reports its earnings Wednesday, the people said, asking not to be named because the information isn't public yet.

"We are not confirming timing. Our employees are our priorities and we will communicate with them first," GM spokesman Pat Morrissey told CNBC Friday.

The involuntary cuts aren't as steep as previously thought.

GM offered buyouts to 17,700 employees in North America with at least 12 years of service in November, according to a document obtained by CNBC at the time. The company was aiming for 8,000 voluntary buyouts, the company previously confirmed. About 2,250 workers accepted severance agreements by Nov. 19, the company previously confirmed. Roughly 1,500 contract jobs have since been eliminated, according to one of the people briefed on the layoffs.