The top South Korean mobile telecommunications service carrier said in a Helio online report the joint venture established last year between SKT and Internet service provider Earthlink starts cellular voice and data services after six months of preparation.

Helio provides the services by renting networks from such U.S. operators as Sprint and Verizon. This measure is the so-called partial mobile virtual network operator (MVNO) system, according to SKT.

The $440-million joint venture will introduce services never before provided in the United States, such as mobile blogging on MySpace, a U.S. Internet blog which claims over 68 million members, and Korean-language wireless Internet service.

Helio expects to acquire 3.3 million subscribers and achieve $2.4 billion in annual sales revenue in the U.S. mobile communications market by 2009.

The service will initially be available in 1,000 retail locations by the end of May, expanding to more than 3,000 nationwide by year-end, SKT said.

SKT, known for launching the world's first commercial CDMA cellular service, now claims 19.7 million subscribers, or 50.7 percent of South Korea’s entire subscription community.