O'Connor was most recently COO of iStar Financial Inc. During his 10-year tenure there, he was responsible for developing and managing that company's risk management and due diligence operations, participating in the evaluation and approval of new investments, coordinating information systems and managing the post-acquisition integration of several corporate acquisitions, according to a release. Before joining iStar, O'Connor was a VP at Morgan Stanley, responsible for the performance of over $2 billion of assets acquired by the Morgan Stanley Real Estate Funds. Prior to that, he held positions at Greystone Realty Corp. and Exxon.

As president of Gramercy, O'Connor will assume a broad range of responsibilities, with a particular focus on completing the integration of its Gramercy Realty unit into the company and producing greater operational efficiencies, the release states. Gramercy Realty consists of many of the assets and staff that formerly comprised American Financial Realty Trust, which Gramercy acquired earlier this year for $3.3 billion. The AFR unit manages a portfolio of net-lease commercial properties totaling 29.2 million square feet.

The hiring of O'Connor follows Gramercy's modification of its management agreement with SL Green Realty Corp, its largest shareholder. As GlobeSt.com previously reported, the modifications include reduction or elimination of certain fees. Eliminating the fees will improve Gramercy's operating performance and cash flow by approximately $20 million per year, Holliday said during last month's Q3 conference call.