News Corp.’s Fox Intl. Channels and Colombia’s RCN Television, the group behind “Ugly Betty,” have joined forces to launch Spanish-language TV network MundoFox in the U.S., a move that will test the media conglom’s successful track record with new TV launches against a crowded market.

MundoFox aims to be carried on stations covering 75% of U.S. households and is finalizing several affiliate deals in leading Hispanic markets across the country. It will take on giant Univision and smaller rival Telemundo as well as Telefutura and Azteca America in the Spanish-language TV arena.

Fox believes there’s enough interest in the sector to go around.

The launch of the net this fall will come after the 2010 census showed consistent strength in the nation’s Hispanic and Latin American population.

“There is still room for growth in the U.S. Hispanic advertising market,” said FIC CEO Hernan Lopez.

Insiders have long argued that ad rates and visibility for Spanish-language TV, which regularly beats top networks in the ratings for certain broadcasts, have long lagged behind their actual reach and influence.

A consortium of private equity firms owns Univision, with Haim Saban as chairman. Telemundo is backed by deep-pocketed Comcast, parent of NBCUniversal, which has vowed to boost its standing.

Univision has planted its upfront presentation this year on Tuesday, May 15 for maximum visibility during the critical week when networks unveil their fall schedules for advertisers. Its presentation “will help marketers understand the New American Reality, where the 50 million-plus Hispanic population is re-shaping the nation and, for many brands, represents an untapped $1 trillion economy,” the network said.

Fox said MundoFox would seek to bring the Fox Network sensibility and RCN’s primetime content to U.S. Hispanic auds.

FIC owns a 51% stake in Colombia’s Fox Telecolombia, which produces primetime content for RCN and FIC, including hit RCN telenovela “El Capo” and the original “Betty la fea.”

“There is an increasing demand for quality Spanish-language content in the U.S. from both viewers and advertisers,” said Lopez. “Fox saw similar dynamics in play 25 years ago when it launched the Fox network, and it would be a missed opportunity not to provide an alternative for the 50-plus million Latino viewers who currently have limited options in Spanish-language broadcast television.”

Along with the Fox broadcast net, cabler Fox News has also been a smashing success.

The new web will include sports programming from Fox Deportes, major motion pictures, two newscasts a day and original Fox Telecolombia skeins such as “Tiempo Final.” The Shine Group, started by News Corp. chairman Rupert Murdoch’s daughter Elisabeth, will produce its first original Spanish-language content for MundoFox.

A search is underway for an exec to head the L.A.-based network.

RCN is one of the largest producers and exporters of Spanish-language television in the world and operates cable channels throughout the Americas.

It has mainly provided content to Telefutura, the sister channel of Univision. “El Capo” was a major hit for Telefutura with its finale luring 1.2 million viewers in the 18-49 demo. No new RCN productions have been committed to other U.S. Hispanic webs this year in anticipation of the MundoFox launch.

FIC operates 350 channels in 35 countries, and a consortium of three cable networks targeting the U.S. Hispanic consumer: FOX Deportes, Utilisima and NatGeo Mundo.