Mechanical Technology Inc. sold 44,500 shares of Plug Power Inc. stock last week, according to documents filed Tuesday with the U.S. Securities and Exchange Commission.

The shares were sold between May 5 and 9 for $5.09 to $5.19 each. MTI, which is developing a methanol-powered fuel cell to operate portable electronics, has been cutting its stake in Plug to help cover those costs and drive down debt.

MTI now owns about 7.4 million Plug shares.

Plug, based in Latham, makes fuel cells for residential and commercial use.

Shares of the company (Nasdaq: MKTY) closed Tuesday at $2.47, down 4 cents. -- Kenneth Aaron

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