Commercial real estate in the Boulder Valley recently has attracted some powerful national investors and developers. From Longmont to Boulder, hefty sums have been doled out for office and retail properties.

Most recently, Seattle-based Unico Properties Inc. purchased a 56 percent stake in Pearl Street Mall Properties Inc., including 15 buildings encompassing 356,000 square feet of retail, office and restaurant space. The portfolio includes some of downtown Boulder’s most historic properties and has long been owned by J Nold Midyette.

Unico’s entry into the Boulder market brings a well-heeled investor to the Boulder Valley. The company owns some 14 million square feet of space, including several properties in the Denver area.

Midyette was just the latest local real estate magnate to sell. Among other recent transactions:

• In December, Goff Capital Partners of Texas paid $67.9 million for 19 buildings in Flatiron Park, including 740,000 square feet of office, flex and warehouse space. Like Midyette, Flatiron Park Co. owners Larry Frey and Ed McDowell began thinking about selling as they approached retirement.

• Circle Capital Partners, which acquired the former Pratt portfolio in Longmont in 2005 for $142 million, sold a portion of those holdings — three buildings — in October to an arm of Fortress Investment Group LLC, for $28.1 million.

• Karlin Real Estate of Los Angeles paid $9 million in fall 2010 for the former headquarters of the Daily Camera at 1048 Pearl St. in downtown Boulder, where Karlin plans a redevelopment.

• NewMark Merrill Mountain States acquired Twin Peaks Mall in Longmont for $8.5 million (bankruptcy price) in February, with plans to redevelop the property.

• Ramco-Gershenson Properties Trust of Michigan paid $69.2 million for Harvest Junction shopping center in Longmont in June.

These transactions — and others like them, including huge new office projects in Broomfield — demonstrate solid investor interest in Boulder Valley’s commercial real estate. But they also represent something more important: a confidence in the future of the region’s economy.

While such confidence is fairly widespread among local business owners, it’s a good thing to see it mirrored by those on the outside.