The Rudin family has obtained 100 percent ownership of One Battery Park Plaza, a 35-story, 885,000-sq.-ft. office building, by acquiring the Rose family’s 50 percent interest in the property. The Rudin family says the move is part of a campaign to grow its presence in Manhattan’s downtown business district.

The Rudin and Rose families jointly built the tower in 1970, but their partnership was actually forged back in 1962 when patriarchs Samuel Rudin and David Rose began assembling the site for the building, which is also known as 24 State Street.

“This transaction reaffirms the Rudin family’s commitment to downtown and our belief that Lower Manhattan’s recovery continues,” Bill Rudin, co-vice chairman and CEO of Rudin Management Company, noted in a statement. Rudin Management Company is a full-service real estate organization and the operating arm of the Rudin Family holdings.

“We’re tremendously proud of our nearly 50-year partnership with the Rose family and the incredible working relationship we’ve enjoyed with them, which has enabled this Class A building to remain one of the preeminent office properties in downtown market,” added Jack Rudin, chairman of Rudin Management.

Daniel Rose, chairman of Rose Associates, called the Rudin family “ideal partners for half a century” in a statement. He explained, “It is only because of our changing portfolio needs that we chose to transfer our interest to our wonderful partner.”

Adam R. Rose, co-president of Rose Associates, added: “With 38,000 residential units under management, it is clear that we are a residential firm. This was a perfect opportunity to solidify our brand and focus our attention on our core area of activity.”

One Battery Park Plaza’s major tenants include Hughes Hubbard & Reed LLP, Seward & Kissel, Liberty Mutual Insurance Company, The Partnership for New York City Inc, and Mound, Cotton, Wollan & Greengrass.

Besides One Battery Park Plaza, the Rudin family’s other downtown properties include 80 Pine Street, 55 Broad Street, One Whitehall Street, 110 Wall Street and 32 Avenue of the Americas.