The New Zealand government will next week end a 16-month ban on new "field" trials of genetically-modified organisms (GMO), despite opposition from a key political party, government sources said on Friday. A moratorium on the commercial release of GMOs into the environment would be extended for two years, with a few exceptions for very low-risk applications, the sources said. "The current moratorium won't be in place but there will be another moratorium with some exceptions," a source told Reuters. Prime Minister Helen Clark's minority centre-left government relies on the support of seven Green MPs for a majority in Parliament, and the environmentalist Greens have campaigned against GMO field trials. The government has been negotiating with the Greens and the sources said there was broad agreement on the way forward, although details were not finalised. The Greens said last week the government, which has 59 votes in the 120-seat single-chamber parliament, could not take it for granted on "core Green issues". Researchers around the world are modifying the genetic make-up of agricultural products to improve their resistance to pests, disease and weather, or to increase crop yields -- with critics arguing they put "frankenfoods" in the food chain. Around 42 per cent of New Zealand's NZ$31.5 billion (14.5 billion euros) of annual exports involve food, but anti-GMO activists say the South Pacific country of 3.8 million people and 44 million sheep, should sell itself as clean, green and free of GMOs. Scientists have warned that without GMO research and trials New Zealand is likely to be left behind while the country's largest company - dairy processor Fonterra Co-operative Group - has warned it could move its research functions offshore if GMO research was curtailed. The new rules would allow scientists to resume field trials, while the government would impose strict controls on containment of experiments by ring-fencing them behind environmental "buffer zones", the sources told Reuters. Rules would also limit the types of genetic engineering experiments that could be tested outside of the laboratory. The government negotiated the current moratorium, due to expire on October 31, with science and industry groups in June last year while it carried out an inquiry into GMOs, the Royal Commission on Genetic Engineering. The government's formal response to the commission's findings is due to be announced a day before the current ban ends. "It's very much the middle way forward as the Royal Commission suggested," a government official said. The inquiry recommended loosening the curbs on low-risk GMO applications, but also sought tougher rules for high-risk ones. There has also been disquiet within Clark's Labour Party and her coalition partner the leftwing Alliance. Indigenous Maori MPs in both parties have been reluctant to approve the release of GMOs for cultural and religious reasons. Extending the ban on the general release of GMOs into the environment would allow the issue to be addressed again after the next election due in just over a year, the sources said. "The odds of that being lifted in two years will depend on the outcome of the election," a government source said.