The company, Bloomberg LP, said Wednesday that current CEO Daniel Doctoroff will step down at the end of the year.
Doctoroff was a deputy mayor under Bloomberg. His departure makes way for Bloomberg to take back the helm of the company, of which he still owns more than 85 per cent.
The 72-year-old Bloomberg handed the reins of America's largest city to Bill de Blasio on Jan. 1.
In a statement, Bloomberg said he never intended to return to his company after 12 years as mayor. But after reacquainting with its operations, he said, he could not resist its lure.
"I have gotten very involved in the company again and that led to Dan coming to me recently to say he thought it would be best for him to turn the leadership of the company back to me," said Bloomberg, whose company has grown to employ more than 15,000 people in 73 countries and has made him a billionaire.
Doctoroff joined Bloomberg LP in 2008 and became CEO in July 2011. Before that he served six years as Bloomberg's deputy mayor for economic development. He said he had no job lined up but in the short term would focus on his not-for-profit interests.
Bloomberg, whose fortune Forbes estimates at $33.2 billion, credited Doctoroff with guiding the company through the financial crisis of 2008 and the deep recession that followed.
Bloomberg LP is privately held and is not obliged to divulge financial information, but it said Wednesday that its revenue grew to more than $9 billion this year from $5.4 billion in 2007. Its subscribers have grown to 321,000 from 273,000, it said, while it added more than 500 reporters and editors.