Lexington is an "UPREIT", which holds most of its properties in subsidiary operating partnerships. An owner can contribute a single-tenant property to one of these partnerships in exchange for partnership units without causing a taxable event. The partnership units pay a dividend equal to Lexington's common share dividend and are exchangeable for common shares on a one-for-basis. Tax would generally be payable at the time of conversion.
Property for partnership unit exchanges are preferable to direct ownership for many reasons. Instead of owning a single property, an investor owns part of a diversified portfolio. In addition, liquidity is easy to realize because Lexington shares trade on the New York Stock Exchange.