Sam Zell's Equity Commonwealth is ready to make its exit from another urban office market.

Equity has put 1735 Market St., also known as the BNY Mellon Center, up for sale, the Philadelphia Inquirer reports. The 54-story, 1.3M SF office tower is its last holding in Philadelphia, following the sale of 1600 Market St. early this year and the record-setting sale of Centre Square in 2017.

HFF has been retained to market the property, the Inquirer reports, and is seeking $500M, which would be the most expensive single-property sale in the city's history by almost $150M (The former 30th Street Post Office building, now fully occupied by the IRS, set the current record at $354M when it was purchased by a Korean investor in 2016). After key departures from FMC and Sunoco, Equity undertook a renovation and has since brought occupancy back up to 91%, the Philadelphia Business Journal reports.

Equity Commonwealth has been selling its office assets since 2014, having brought in around $6.1B from such transactions, according to the PBJ. In July, the company completed its exit from its home market of Chicago with its sale of the Triangle Plaza.

Equity founder and primary shareholder Sam Zell came under fire earlier this summer for vulgar and dismissive comments made about the #MeToo movement of increased awareness surrounding sexual harassment and assault, but his businesses do not seem to have suffered any ill effects.