Earvin "Magic" Johnson’s real estate development firm has lost more than $8 million after selling an apartment complex the company built.

Canyon-Johnson Urban Funds, a combination of Johnson and Canyon Capital Realty Advisors of Los Angeles, sold the building at 30 Caldwell St. in Charlestown for $45.7 million to John Hancock Life Insurance Co. last week, according to media reports. But the project cost $54 million to construct. That’s a difference of about $8.3 million

Mezzo Design Lofts, a 146-unit apartment building, is located near the Sullivan Square MBTA station. The structure is about five years old.