General Motors (GM) is said to have plans in investing $600 million to upgrade Flint Assembly, the company's oldest assembly plant. The firm will set up a state-of-the-art paint facility to keep the plant at par with newer production lines, according to M Live.

On December 16, GM Executive Vice President Mark Reuss told workers and plant managers, "You earned this -- everybody who works hard every day. These are investments in the future (that will last) for a long time."

The Flint investment was part of a broader announcement of around $1.3 billion in GM investments in five US plants: Flint, Toledo, Ohio, Detroit and Romulus, and Bedford, Indiana, the report detailed.

Based on the company's website, the new paint shop will be the third one in North America to use a wet-coat paint process that is environmentally friendly, the report said.

GM officials said site work in the Flint plant will start on January 2014. The construction of the new facility will begin in 2014's second quarter. The paint facility will be completed in 2016 with first units set to be painted in October 2016, M Live reported.