Andrew Mathias' 17-year tenure as president of New York office landlord SL Green is coming to an end.

The publicly traded real estate investment trust announced Tuesday that it wouldn't be renewing Mathias' employment contract, which expires at the end of 2023. Mathias will step down as president but continue to serve on SL Green's board of directors and as an adviser to CEO Marc Holliday.

“Andrew has been a true partner in everything we’ve accomplished at SL Green from the very beginning, working side-by-side to take this company from IPO to the undisputed market leader in New York City,” Holliday said in a statement. “Andrew’s imprint will be felt on this company for years to come, as his vision and leadership live on across our entire portfolio and the countless team members he has mentored.”

Mathias joined the firm in 1999 but quickly rose up the ranks, being named chief investment officer in 2004 and president in 2007. He was appointed to the board of directors in 2014. SL Green said in a regulatory filing that Holliday, who is chairman of the board, would temporarily add president to his list of titles.

“It has been an extraordinary experience helping to lead this industry-leading company for nearly a quarter century, and I couldn’t be prouder of everything we’ve achieved for our shareholders, our employees and our city,” Mathias said in a statement. “We have a proud history at SL Green of developing and empowering young talent, and I look forward to seeing our next generation of leaders flourish and take SL Green to the next level.”

The filing said the decision to end Mathias' employment wasn't the result of any dispute with the company. As part of the nonrenewal and advisory agreement he signed, Mathias will be entitled to an office at SL Green's headquarters at One Vanderbilt for the first six months of 2024.

His two-year employment contract took effect Jan. 1, 2022, and laid out a base annual salary of $950K, plus other forms of compensation that could have totaled more than $6M if certain performance benchmarks were hit.

SL Green is the largest owner of office space in Manhattan, a position that has put it in the crosshairs of office real estate skeptics. Investors are shorting SL Green's stock more than any other office REIT, Bloomberg reported last month, despite its shares being up 11% on the year, outperforming its peers.