An Anglo-Swiss firm specialising in research into genetically-modified (GM) crops has announced it is closing a section of its British laboratories.
Syngenta, whose research centre is at Jealotts Hill in Bracknell, Berkshire, is transferring its plant sciences sector to North Carolina in America.
Some of the 100 posts at the labs will be lost or transferred to the US.
Syngenta's decision comes after huge GM firms Monsanto and DuPont recently reined in their British-based research.
The centre, which has had £10m of investment and currently employs 900 people, will continue to develop agro-chemicals.
A spokesman for Syngenta said: "Our commitment to all the other areas of the business remains the same."