Brookline Bank is reportedly the strongest suitor for the purchase of 131 Clarendon St. in Boston’s Back Bay.

The building is expected to fetch upwards of $13.5 million and is owned by the Beal and Related Cos., according to sources familiar with the deal.

The vacant, approximately 56,000-square-foot property – formerly the home of the Hard Rock Café – is just a shell and would require about $400 per square-foot of improvements and leasing costs on top of the closing price, according to real estate executives.

The owners and the bank, which is seeking branch and office space, will likely have a contract finished in the next week or so, and the deal could be done within two months, according to industry sources.

The building abuts The Clarendon, Beal and Related’s luxury condominium and apartment project, and both properties were purchased as a package deal. Formerly the home of a Hard Rock Café, it is located across the street from the Hancock Tower garage and alongside Stanhope Street.

"It’s a bit of an off location in that it’s not on Boylston or Newbury Street, but it is in the Back Bay, and unlike two years ago there’s very little retail vacancy in the Back Bay," said one real estate professional about the location.

Brookline Bank did not return calls seeking comment.