Ineos said TGE is the preferred bidder to build a huge ethane tank at the site in Scotland, with completion due in 2016.
Two plants dating from the 1960s will close, but Ineos said there will be no job losses from the changes, which are part of its £300 million survival plan agreed last year.
The firm had threatened to close part of the site because of industrial relations problems.
Ineos said the ethane gas terminal was essential as it looked to replace existing North Sea feedstocks that were running out.
Harry Deans of Ineos said: "The ethane tank will be the biggest in Europe. It is a crucial part of our survival plan that will enable us to import shale gas from the USA.
"By 2016 Grangemouth will be a shale gas based facility, essential for it to become a profitable business again."
Ineos said its old ethylene cracker and associated Butadiene plant will close with immediate effect so it could concentrate on increasing production from its more modern facilities on the site.
Mr Deans added: "We are pleased to be able to redeploy all affected staff into other roles across the Grangemouth site as we focus on the future."
Around 1,300 people work across the Grangemouth sites.