INEOS has agreed to supply ethane from US shale gas to ExxonMobil’s chemical plant in Fife in a deal it said would help to underpin the competitiveness of a major Scottish manufacturing facility and to secure jobs.

The chemicals giant has signed a long term sales and purchase agreement with ExxonMobil and Shell under which the Fife Ethylene Plant at Mossmorran will receive ethane from INEOS’s new £450 million import terminal in Grangemouth.

The Mossmorran plant will use the gas to make ethylene, which is a key input in the manufacture of products ranging from plastic bags to paints.

INEOS said the agreement would provide a major boost for the Mossmorran plant by giving it access to secure supplies of relatively low cost gas from US shale areas.

ExxonMobil said the new source of ethane will help offset declining North Sea supplies.

The additional supplies, which will be available from mid 2017, could help ensure that Mossmorran can run at the kid of production levels needed to maximise efficiency.

ExxonMobil said the agreement benefits the 140 permanent staff and 50 contractors working at the Fife plant, and the local community’s economy.

Led by Jim Ratcliffe, INEOS believes the agreement provides an example of how investment in developing shale resources in the UK can provide a spur to the wider economy.

“We know that ethane from US shale gas has transformed US manufacturing and we are now seeing this advantage being shared across Scotland,” said the company.

In December an analysis by PwC found shale gas had given US manufacturing a boost through significant cost savings and jobs creation.

ExxonMobil has been producing ethylene at Mossmorran since 1985. It says the plant is one of Europe’s largest and most modern ethylene plants, with an annual production capacity of 830,000 tonnes.

Shell’s chemicals arm has the right to 50 per cent of the plant’s capacity.

INEOS has commissioned eight ships to carry ethane from the US to Grangemouth and its Rafnes plant in Norway.