Ron Klain, Vice President Joseph Biden’s chief of staff, will leave the White House in late January to become the president of Case Holdings, the holding company of AOL co-founder Steve Case, administration officials confirmed Tuesday.

“I have been honored to serve in the Obama-Biden administration, and to work again for Vice President Biden, who has been my mentor, friend, and role model for more than 25 years,” Klain said in a statement. “It is a hard choice to leave the Vice President’s office, and especially hard to leave such wonderful colleagues. But this is a rare opportunity to work with Steve and Jean and the terrific team they have assembled, and to take my business and legal career to a new level.”

In his new role, Klain will help oversee the group’s business interests and provide counsel on philanthropic endeavors.

Biden praised Klain, who also previously served as chief of staff to Vice President Al Gore, for doing “an exceptional job of building my team, implementing my direction on top priorities, and providing invaluable counsel.”

The vice president added that he is “proud of the successes we have had over these two years, and am grateful for the role Ron played in achieving them.”