An April 28 foreclosure sale has been set for Audubon Park because its owner – 16 Miner Street LLC, which is headed by developer Robert Fox – defaulted on a construction mortgage.

Built in 2007, the 53-unit condo development is in the Audubon Circle area of the Fenway. Forty-one of the 53 condos, along with 22 of the six-story building’s 32 parking spaces, are scheduled to be sold to the highest bidders.

Fox could not be reached for comment yesterday. The project’s lender, IndyMac Venture LLC, declined comment.

With Audubon Park, Fox tried to establish a higher pricing for condos in what’s considered a “pioneering” location – a hard proposition when the real estate market is leveling off or softening, said Kevin Ahearn, president of Otis & Ahearn, a Boston real estate brokerage.

A challenging market usually sends buyers on a “flight to quality” – established premium neighborhoods that feel like a more comfortable investment, he said.

Year-to-date Fenway real estate sales represented just 2 percent of downtown Boston transactions through Friday, compared to 6 percent for the same periods last year and in 2008.

After Audubon Park’s condos failed to sell, Fox started offering a portion of them as apartment rentals.

“It was a two-prong marketing approach that he was using: Sell some but retain some to ride the market back up again,” Ahearn said. “I think it was a correct strategy, whether or not he was able to buy that time and make that happen.”