FORT COLLINS -- An Arizona-based real estate investment group that two years ago bought the former LSI Logic Inc. building at Harmony and Ziegler roads has raised its stake with the $5.25 million purchase of another big office building nearby.

Lone Cactus LLC, a group of Phoenix investors, has closed on the purchase of the 50,000-square-foot former home of Heritage Christian School at 4800 Wheaton Drive.

Heritage shut its doors at the end of the last academic year, and reconstituted as Heritage Christian Academy in a much smaller north Fort Collins location.

The same buyers, under the name Arizona Land Co. LLC, in May 2006 paid $12.6 million for the LSI property, a 120,000-square-foot office building that had been empty for nearly a year after LSI consolidated its operations at another south Fort Collins location.

Peter Kast and Larry Stroud, partners in Realtec Commercial Real Estate Services Inc. of Fort Collins, listed the Wheaton Drive property for Heritage Christian. Kast said the sale shows the strength of the Fort Collins investment market by bringing in a known buyer to take another big share. "Obviously, they're very interested in the Harmony corridor," Kast said.

Stroud and Kast will handle brokerage of the space, with lease rates at $15.50 per square foot, triple-net. The buyers were represented by Mary Francis Cowan, a broker with Colorado Springs-based Grubb & Ellis/Quantum Commercial Group. She also handled the Arizona group's purchase of the LSI building.