Capstone Turbine Corp. announced on Thursday an offering of 18.8 million shares to a single institutional investor that will raise $30.2 million.

The Chatsworth company will use the proceeds for working capital and for other general corporate purposes. The company develops and manufactures low-emission microturbine systems.

The offering, which is set at $1.70 a share, is expected to close Tuesday. The offering will gross $32 million with a net of $30.2 million after the subtraction of underwriting discounts and commissions. The investor was not disclosed.

Cowen and Company, LLC, in New York, and FBR & Co., in Arlington, Va., are acting as the book-running managers of the offering. Craig-Hallum Capital Group, LLC, in Minneapolis, is co-manager of the offering.

Shares closed down 28 cents, or less than 14 percent, to $1.78 on the Nasdaq.