LaSalle Investment Management Inc. sold a 14-story office building in Boston's Financial District for about $238.7 million to an affiliate of Synergy Investments, Banker & Tradesman reported, citing data from the Suffolk County Registry of Deeds.

The 10 Post Office Square building offers 163,834 square feet and is assessed at about $54.9 million, the publication wrote.

The buyer financed the acquisition using a $122 million mortgage through Principal Life Insurance Co. unit Principal Real Estate Investors LLC, according to the publication.