Plymouth-based auto supplier Metaldyne Corp. will sell off its plant in Middleville, southeast of Grand Rapids, and another one in Niles, Ill., the company announced Tuesday.

Earlier this year, the company closed its chassis facilities in Farmington Hills and in Greenville, N.C., as well as an administrative office in Plymouth.

The Middleville operation machines front engine covers, oil pumps and other components. Niles is an aluminum die casting facility.

Proceeds from the sales will be used to pay down debt or for general funding purposes.

Metaldyne is an indirectly, wholly owned subsidiary of Asahi Tec Corp., a Shizuoka, Japan-based chassis and powertrain component supplier in the passenger car/light truck and medium/heavy truck segments.

Metaldyne has annual revenues of approximately $1.8 billion. The company employs more than 6,300 employees at 33 facilities in 14 countries, according to a company statement.