SEATTLE—Ivanhoé Cambridge, and its partner Callahan Capital Properties are spending about $280 million for two downtown adjoining office properties totaling more than 700,000 square feet on 39 floors.

The partnership will gain 100% interest in 1111 Third and Second & Spring. 1111 Third is a 34-story, 572,500-square-foot class-A office building that has recently undergone significant capital improvements, including an upgraded lobby and storefront, new building systems and an expansive new fitness center. Located in Seattle's vibrant downtown core, the property features outstanding views of Elliott Bay and the Olympic Mountains, as well as a six-level underground garage, convenient access to public transportation, freeways and an abundance of nearby retail and dining amenities.

Second & Spring, located at 1100 2nd Avenue, is an adjoining five-story, 135,000-square-foot historic office property constructed in 1906 and redeveloped in 2013. The building offers high-quality creative space with 15-foot-high exposed ceilings, 26,000-square-foot floor plates and an extensive window line allowing an abundance of light.