Ronald Rubin plans to step down as a trustee of Pennsylvania Real Estate Investment Trust, severing his formal link to the company that he's helped define since it acquired his Rubin Organization in 1997.

PREIT said in a statement Wednesday that Rubin has opted not to stand for reelection at the retail landlord's next annual shareholders' meeting on May 31.

Rubin, 86, said in an interview that he was leaving PREIT's board to focus on his family real estate holdings, such as the historic Bellevue hotel and office building on South Broad Street.

Rubin became chief executive of what had initially been called PREIT-Rubin following the acquisition of his Rubin Organization real estate firm. PREIT's current chief executive, Joseph Coradino, took over the role in 2012, when Rubin became executive chairman, a position he held until January 2016.

It was under Rubin's leadership that PREIT purchased the Gallery at Market East shopping mall, which is in the process of being redeveloped into a new retail destination to he called Fashion District Philadelphia.

The company also spent extensively on renovations to Cherry Hill Mall under Rubin's watch, cementing its place as a regional retail powerhouse and the crown jewel of the company's suburban shopping-center empire, which also includes Willow Grove Park, Moorestown, and Plymouth Meeting Malls.

"I want to thank Ron for his many years leading the company and on the board," Coradino said in the Wednesday statement. "As a mentor to me, personally, I learned a lot from Ron and know the lessons will stay with me for life.  We wish Ron continued to success in future endeavors."