Honda Motor Co.'s Thai unit on Thursday officially opened a new assembly and engine plant around 120 km northeast of Bangkok.

Construction of the plant at the Rojana Industrial Park began in 2013, with the automaker investing 17.15 billion baht (around $485 million). It will have a maximum production capacity of 120,000 vehicles per year and employ some 1,400 people.

Honda Automobile (Thailand)'s Chief Operating Officer Pitak Pruittisarikorn said the new plant in Prachinburi province will allow total production in Thailand to reach 420,000 units per year.

He said advanced technology from Honda's assembly plant in Yorii, Saitama Prefecture, was incorporated into the new Thai facility, helping to shorten production and lessen the environmental impact.

The new plant began producing engine parts in February, followed by mass production of the latest Civic sedan. But most of its production is still based at its plant in Ayutthaya province, north of the capital.

Honda moved to build its production base on higher ground in Prachinburi after devastating floods in 2011 forced the temporary closure of its Ayutthaya plant.

The launch was attended by Thai Deputy Prime Minister Somkid Jatusripitak and Japanese Ambassador to Thailand Shiro Sadoshima along with Honda executives.