Blocked by Mexican regulators in his bid to tap television in his home country, where he hopes to challenge the reign of broadcasters Televisa and TV Azteca, Slim is pivoting toward a less-protective market.
Slim's America Movil, one of the world's biggest telecommunications firms, will fund the venture. Financial details were not disclosed.
Last year the company purchased Miami-based DLA Inc, a digital media firm that distributes movies and television series from U.S. entertainment houses, as well as music to televisions and smartphones.
Slim's new online venture, Ora.TV, will be based in the United States and could launch in the third quarter of this year, a spokesman for Slim told Reuters on Monday.
The telecommunications tycoon last week was named the world's richest man for the third year in a row, according to Forbes magazine's annual list of billionaires.
The free online news and entertainment channel will have mostly English-language content in its initial phase.
One analyst said he awaited more details in order to have a better idea of the implications for America Movil.
"I think this is a very long-term effort," Santander analyst Gregorio Tomassi said. "I'm not sure what the model is as far as Latin America is concerned. I would like to know how much money (they are investing)."
Slim's spokesman, Arturo Elias Ayub, said that the business model "will be based on advertising and probably (down the road) there could be channels that may want to broadcast it exclusively." He declined to elaborate further.
The venture will have a New York headquarters and Los Angeles studios to produce on-demand content and "a wide range of programs that transcend traditional formats," Ora.TV said.
Jon Housman, formerly the president of digital journalism at Rupert Murdoch's News Corp, will front Ora.TV.
Slim is Latin America's main provider of pay television, offering cable and satellite services to around 13 million customers, and also owns a stake in New York Times Co.
Though barred from competing in Mexico's traditional television market, he operates local online news site Uno Noticias which airs sports and cultural programs for free.
In December, Mexico's telecoms watchdog, Cofetel, was planning to look at whether Uno Noticias violated Slim's operating licenses. But regulators have yet to comment.
Cofetel could not immediately comment on Slim's latest television venture on Monday.
President Felipe Calderon's conservative administration has been hesitant to approve Slim's entry into the television market, fearing it would make the tycoon too powerful.
If Slim expanded into Mexican television, he would put pressure on the duopoly of Televisa and Azteca. The companies have jealously guarded their territory, helping vanquish a potential rival back in 2006. (Additional reporting by Michael O'Boyle, Tomas Sarmiento and Patrick Rucker.; editing by Matthew Lewis)