Dreaded white-collar job cuts at General Motors Corp started on Tuesday as the wounded automaker began to deliver on promises to the government to shrink its work force so it can be profitable at lower sales levels.

On Tuesday morning, GM told 160 people at its manufacturing engineering operations in Warren, Michigan, that they would be laid off as of April 1, spokesman Tom Wilkinson said.

It's the beginning of 3,400 salaried layoffs in the US and part of the 47,000 job cuts that GM wants to accomplish worldwide by the end of the year, Wilkinson said.