Descendants of John D. Rockefeller Jr. will vacate office space at 30 Rockefeller Plaza that the family has occupied for more than 80 years.

The Rockefeller family will leave Room 5600, the full-floor space on the tower’s 56th Floor, in the third quarter of 2015, and relocate to a new office a block south at One Rockefeller Plaza, said Fraser Seitel, a family spokesman. The Rockefellers have been occupants of Room 5600 since 1933, he said.

“They needed slightly less space, their lease was up and they got a good, reasonable deal,” Seitel said in a telephone interview yesterday.

The new office, combined with space leased by the wealth- management firm Rockefeller & Co., will give the family a 75,000-square-foot (7,000-square-meter) presence at the property, developed by John D. Rockefeller during the Great Depression. Rockefeller Center is owned by Tishman Speyer Properties LP.

“We are thrilled to remain in Rockefeller Center, which has been our home since Father built the Center in the 1930s,” David Rockefeller Sr., the family’s 99-year-old patriarch, said in a statement yesterday. “Under Tishman Speyer’s stewardship, Rockefeller Center remains the heart of New York City.”

The Rockefeller family office has moved five times since its establishment in 1882, according to the statement. It was located at 26 Broadway for 49 years before moving to Midtown in the early 1930s. The office supports family members’ charitable activities and entrepreneurial ventures, Seitel said.

“We are extremely honored to continue our decades-long association with the Rockefeller family and are grateful that they will maintain their home at the iconic New York complex that bears their name,” Jerry Speyer and Rob Speyer, Tishman Speyer’s co-chief executive officers, said in the statement.

The six branches of the family are descended from John D. Rockefeller Jr. and his wife, Abby Aldrich Rockefeller, and represent five living generations.