Local business briefs

Tennant buys Scottish Green Machines firm Tennant Co. of Golden Valley agreed to buy Applied Sweepers, which manufactures the Green Machines brand of cleaning equipment, for about $68 million. Tennant, which makes industrial floor-maintenance equipment, said Applied Sweepers' management will stay with the company. Applied Sweepers, a privately held company based in Falkirk, Scotland, had 2007 revenue of about $40 million. Tennant's 2006 annual revenue was $598.98 million. The deal is expected to close by the end of February or early March.

DOW JONES NEWS SERVICE

Xcel puts plant upgrade at $100 million-plus Xcel Energy Inc. said that a proposed expansion of its Monticello nuclear power plant would cost $100 million to $135 million. Xcel filed an application with the Minnesota Public Utilities Commission asking regulators to approve the expansion, which would add 70 megawatts to the plant's current 600-megawatt capacity, now about 10 percent of the utility's power. The Nuclear Regulatory Commission, which must also approve the expansion, has licensed the Monticello plant until 2030.

H.J. CUMMINS

Boston Sci court fine jumps by $69 million A patent judgment against Boston Scientific Corp. has jumped to $501 million, after a judge tacked on $69 million in interest. U.S. District Judge John Ward expanded the damages award -- decided by a federal jury in Marshall, Texas -- to cover interest on royalties dating to the medical device maker's 2004 U.S. launch of drug-coated heart stents. After deliberating less than two hours, jurors awarded $432 million on Monday to Dr. Bruce Saffran, who argued the stents violated his 1997 patent.

BLOOMBERG NEWS

NASA awards Alliant $812 million contract Alliant Techsystems Inc., the only maker of reusable solid-fuel rocket engines for the space shuttles, won an $812.5 million NASA order to continue delivering the systems until the spacecraft are retired. Under the extended contract, Edina-based Alliant will produce or refurbish engines used in shuttle flights and ground testing until Sept. 30, 2010, when the program ends, the National Aeronautics and Space Administration said. Work on the engines will be done in Utah and at NASA facilities in Huntsville, Ala., and in Florida.

BLOOMBERG NEWS