He will take over the leadership of Bloomberg LP next year following the resignation of CEO Daniel Doctoroff, the company said late Wednesday.

The decision is a stunning reversal from Bloomberg’s instance during his 12-year tenure as mayor that he would never return to his namesake business. But he said in a statement that the more time he spent reacquainting himself with the company, the more “the more exciting and interesting I found it.”

Bloomberg founded Bloomberg LP in 1981 to provide real-time financial information for stock traders and investors. It gradually grew into an international powerhouse spanning news, television, and stock market data. As majority owner, Bloomberg became one of the wealthiest scions in America worth in excess of $30 billion. He later capitalized on his entrepreneurial image and moderate politics to win three terms as New York’s mayor, leaving office just eight months ago.

Since then, Bloomberg, 72, said that he has spent a lot of time at the company, and that it prompted Doctoroff’s departure.

“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,” Bloomberg said in the statement. Doctoroff, who served in Blooomberg’s mayoral administration, joined the company as president in 2008 and then became CEO in 2011.

During Doctoroff’s tenure, Bloomberg’s revenue has grown to more than $9 billion this year, from $5.4 billion. The number of Bloomberg terminal subscribers – the company’s cash cow – rose to 321,000 from 273,000.

Doctoroff said in a statement: “I love the company and have deep respect and affection for Mike, so leaving is not an easy decision, but it is the right one for the company, for Mike and for me at this stage of my life. It is and has always been Mike’s company and given his renewed interest and energy, it only makes sense for him to retake the helm.”