Mark Hoffman, Chairman of CNBCMark Hoffman, Chairman of CNBC

The president and chairman of CNBC will step down in September.

His departure is his own. Cesar Conde was hired by NBCUniversal to lead NBC News, MSNBC and CNBC.

Sullivan will take over as CNBC's president. Sullivan has been with NBCUniversal for the last two years and is based in London. He was the president and managing director of CNBC.

Sullivan will return to the U.S. Conde wrote in a note to NBCUniversal employees that Hoffman would remain as a consultant through the transition.

Conde said that Mark has overseen the steady growth of CNBC as the world's #1 business and money news brand. The reach and influence of CNBC is testament to Mark's leadership.

Even as millions of Americans abandon linear cable TV, CNBC is one of NBCUniversal's most profitable assets. CNBC has increased profitability in 16 of the 17 years it has been run byHoffman. According to a person familiar with the matter, CNBC's profitability is going to grow in the next few years.

"We are in the business of business so it's important to note we've never been more profitable, setting record after record in financial performance, year after year, as we maneuvered through economic cycles, exogenous events and the historic secular change that accompanies the information age."

After joining CNBC in 1997 he went on to work at local TV stations. He returned to CNBC in 2005 and immediately pushed to acquire 50% equity interests in CNBC Europe and CNBC Asia.

In the past six years, CNBC.com has grown from 30 million unique monthly readers to 200 million.

Most of CNBC's revenue comes from the cable network side. CNBC's leadership as a trusted source of news, especially for wealthier Americans, has been maintained by the renewal of contracts for notable TV personalities.

CNBC is a global multimedia powerhouse that many thought would never fully recover from the dotcom bubble bursting, but now it is a powerhouse in the digital age.

CNBC TV has been the top business news platform for 29 years in reaching Americans who make more than $125,000 a year.

CNBC is owned by NBCUniversal.