HOUSTON (Reuters) -Chevron ( CVX ) will lay off 15% to 20% of its global workforce, the U.S. oil company said on Wednesday during an internal employee town hall meeting, according to a source familiar with the matter. 

The planned layoffs come as the company has said it is targeting $3 billion in cost cuts through 2026 from leveraging technology, asset sales and changing how and where work is performed.

The company told employees they can begin opting for buyouts now through April or May, the source said.

Staffers will be selected and notified if they are part of the layoffs by May or June, according to a slide presentation seen by Reuters.