William Schomberg BRUSSELS, Sept 13 (Reuters) - Environmentalists and some of Europe's biggest companies have formed an unusual alliance to try to stop the European Union from extending anti-dumping duties on Chinese energy-saving light bulbs for one more year. Environmental group WWF, Swedish retailer Ikea [IKEA.UL] and Dutch electronics giant Philips <PHG.AS> are lobbying EU governments to reject the proposal when trade experts meet for what diplomats said was set to be a stormy meeting on Friday. WWF wrote to the British government this week, criticising the plan to continue the duties as inconsistent with EU climate change policies, "narrowly protectionist" and discouraging for manufacturers of energy-saving goods in developing countries. "Any continuation will result in an unnecessary slowing down of the shift from incandescent lamps ... that could contribute to savings of 23 million tonnes of carbon dioxide per year, equivalent to 0.5 percent of EU greenhouse gas emissions," the letter, obtained by Reuters, said. The duties were introduced for five years in 2001, adding up to 66 percent to the price of Chinese bulbs entering the EU. They were due to expire in 2006 but Germany's Osram asked for them to be continued. Ikea, which says it sells about 20 percent of the EU's energy-saving light bulbs, wrote to EU trade experts warning it saw "huge problems in sourcing a sufficient number of low energy light bulbs at a fair and low price" if the duties remain. EU factories account for barely 20 percent of low-energy bulbs sold in the EU and demand is set to rise as Brussels presses on with plans to phase out old-style incandescent bulbs. The light bulbs case is seen as a test of the EU's response to many companies' reliance on cheap imports from China, and the bloc's ability to align its trade and environmental policies. The bloc's Commission last month settled for a compromise plan to extend the duties for a one-year "adjustment" period. EU trade chief Peter Mandelson wanted to axe the duties. But Industry Commissioner Guenter Verheugen blocked him, saying that would cost jobs at manufacturer Osram in his native Germany. Philips imports more lamps from China than Osram and it wants the duties scrapped now. It says Osram could extend them by a further year and a half, on top of the one-year grace period, if it seeks and gets a review of the measures in 2008. In a statement, Philips challenged the idea that no duties meant European layoffs, saying it would hire more workers at its plant in EU country Poland making high-end energy saving lamps. Osram says it is simply seeking to uphold the rules of free and fair trade. Friday's vote in the EU's Anti-Dumping Committee is set to be tight, diplomats said. The result will not be binding but typically the outcomes of such meetings are followed by ministers when taking a final decision on dumping cases. The bulbs case must be settled by mid-October when the duties are due to expire.