A 50,673-square-foot office and retail building in Boston’s Financial District has sold for $5.7 million or $112 per square foot.

Synergy Investment & Development, a Boston-based real estate investment and development firm, bought the building at 101 Summer St. from Aurora Bank FSB.

The sale of the building, also known as the Church Green Building, marks the first downtown Boston investment sale in 2010, according to CB Richard Ellis, who brokered the sale.

The CBRE team of Chris Angelone, Bill Moylan and Matt Pullen marketed the building on behalf of Aurora Bank FSB and procured Synergy Investment & Development.

"We are pleased to add this boutique building to our growing Boston portfolio," said Dave Greaney, president of Synergy Investment & Development.

Capital Crossing Services Co. leases approximately 35,000 square feet at the property, which also has approximately 8,000 square feet of ground-level retail space.

"The 101 Summer St. sale was a highly competitive process and it validated that investors are ready to take lease-up and market risk for well-located assets," said Chris Angelone of CBRE Capital Markets.