Hyundai signs a definitive agreement with China’s Sichuan Nanjun Automobile Group to form a 50/50 commercial vehicle joint venture.

The pact makes good on a memorandum of understanding between the two inked in October.

Named Sichuan Hyundai, the JV initially will operate out of the existing Nanjun Auto CV complex in Ziyang City, Sichuan province.

Each partner is investing $559 million in the new venture. Plans call for Sichuan Hyundai to expand and add a new plant to the Ziyang complex, taking annual production capacity to 160,000 units by 2013.

The JV will market both existing Nanjun Auto trucks and buses, enhanced by Hyundai technology, and a new line of premium heavy-duty trucks and buses under the Sichuan Hyundai badge.

This is Hyundai’s first foray into China’s CV market, which the auto maker forecasts will grow to 5.2 million units in 2015, from 4.3 million in 2010.

Nanjun Auto is China’s 11th-largest CV manufacturer, with current capacity for 120,000 units annually at its plants in Chengdu and Ziyang City.