More than 1,000 businesses attended an event in County Durham which could lead to contracts worth millions of pounds with train-maker Hitachi.
The Japanese firm is already creating at least 500 jobs under plans to build a new generation of inter-city trains at Newton Aycliffe.
On Wednesday about 1,800 people were at an open day to find out how they could become suppliers.
Construction at Newton Aycliffe is expected to start later this year.
A consortium led by Hitachi will build a new factory where rolling stock will be made.
The move is expected to create thousands of associated supply jobs.
Councillor Neil Foster, Durham County Council's cabinet member for regeneration and economic development, said: "The event has been a fantastic success.
"The range of local companies represented is testament to the sound network of supply we are able to offer Hitachi in County Durham and the wider area.
"I would like to thank Hitachi for choosing Newton Aycliffe and assure them we will continue to offer them our full support."