ExxonMobil has announced plans for a 500 million pound investment at its Fawley site.
The proposed project would include new refinery units which would allow it to process a wider range of crude oils.
If successful the plans will support and secure the jobs of 1000 employees.
Fawley Refinery manager, Simon Downing, said: ‘The project is a bold statement of confidence in Fawley and its ability to produce high quality fuels.’
The company will make a final decision on the planned investment before July 2019.