* Construction of new facility to take 15 months
* Upgrade in line with Thai regulatory changes (Adds details)
BANGKOK, July 16 (Reuters) - A Thai unit of Exxon Mobil (XOM.N) plans to invest $394 million in a project to upgrade its oil products in line with Thai regulatory changes in product specifications for gasoline and diesel fuels.
The construction of a new facility as part of this project is expected to take about 15 months and it will start operations on Jan. 1, 2012, Esso (Thailand) PCL (ESSO.BK) said in a statement on Friday.
The Thai government plans to implement Euro 4 standards for diesel with a low sulphur level of 50 parts per million (ppm), or 0.005 percent, from Jan. 1, 2012.
Thailand currently uses Euro 3 specifications for diesel with a sulphur level of 350 ppm, or 0.035 percent.
ExxonMobil Research and Engineering Co, an affiliate of Exxon Mobil, is the management service provider for the project, while Foster Wheeler Inc FWLT.O will be construction contractor.
Esso operates a refinery with capacity of 177,000 barrels per day, accounting for 16 percent of Thailand’s total.
At 0310 GMT, Esso shares were up 0.8 percent at 6.30 baht, while the main Thai index .SETI was 0.37 percent higher. ($1 = 32.21 Baht) (Reporting by Khettiya Jittapong; Editing by Alan Raybould)