The company plans to shift biotech crop research from Jealott\'s Hill, west of London, to North Carolina, with the loss of 130 jobs.
Jealott\'s Hill, which employs a total of 900 people, will concentrate on research into agrochemicals.
\"We need to have the research and development work done in the marketplace where we can most effectively do business,\" said spokesman Andrew Coker.
Europe has resisted the introduction of genetically modified crops, in contrast to the United States where strains of grain, soybeans and other crops modified with foreign genes are now widely cultivated.
Syngenta was the last company to have a significant biotech crop research capability in Britain, following decisions by Monsanto (MON.N: Quote, Profile, Research) , DuPont (DD.N: Quote, Profile, Research) and Bayer Cropscience (BAYG.DE: Quote, Profile, Research) to rein in operations.
The firm\'s move, first reported in the Times Higher Education Supplement, is a blow for UK academic research, given Syngenta\'s sponsorship of much university work, said Michael Wilson, a professor of plant biology at Warwick University.
Equity analysts, however, said the decision was of limited commercial significance, since the biotech work would continue in a different geographical setting.
Shares in Syngenta were trading 0.7 percent higher at 105.75 Swiss francs in a steady European stock market by 0915 GMT. The stock was underpinned by better-than-expected quarterly results from U.S. rival Monsanto on Wednesday which reflecting strong demand from farmers for herbicides.
ENVIRONMENTALISTS CHEER The environmental group Friends of the Earth welcomed Syngenta\'s decision and said the company had misjudged the market for genetically modified crops in Britain and Europe.
In May, the European Union lifted an effective five-year ban on biotech crops which had angered its top trading partners, including the United States.
But the end to the ban applied only to a variety of imported sweetcorn. EU farmers still cannot grow the biotech corn themselves.
The U.S. National Corn Growers Association estimates the U.S. corn industry has lost $250 million annually because of the EU ban on biotech foods.
Through genetic modification, scientists have developed crops that are resistant to disease, insects and weedkillers and supporters of the technology say it will benefit farmers and well as the environment.
But critics fear risks to human health as well as the environment and claim the biotech companies controlling the crops threaten farmer independence.