DETROIT -(Dow Jones)- General Motors Corp. (GM), coinciding with its bankruptcy filing Monday, said it will shutter 17 factories and parts centers by the end of 2011. It will also cut an additional 5,000 salaried jobs. The closures will reduce GM's U.S. facilities to 33 from 47 by 2012. Between 18,000 and 20,000 workers will be affected by the shutdowns, General Motors North America Manufacturing Vice President Tim Lee said during a conference call Monday. Employment reduction will be done according to terms in the United Auto Workers agreement. The closures are expected to result in lower fixed costs per vehicle sold and more efficient capital investment. Plant efficiency is expected to jump with the reduction of the assembly plant count, Lee said. Seven factories in Michigan and plants in Ohio, Indiana and Tennessee will be closed, the auto maker said in a statement. Two of the closures had been previously announced, including a castings factory in Massena, N.Y., which closed May 1.