Australia's Woodside Petroleum announced Friday it was shelving a controversial gas export project worth more than $40 billion, prompting government assurances that the resources boom was not over. The energy giant said the proposed Browse liquefied natural gas development in Western Australia was not a financially sound option. "The development would not deliver the required commercial returns to support a positive final investment decision by Woodside," the company said in a statement to the Australian stock exchange. Woodside CEO Peter Coleman said cost pressures had eroded viability of the onshore precinct at James Price Point, north of Broome, and the project needed a "fundamental change in cost structure". "Our customers are saying to us very clearly 'no longer can we pay for your expensive projects'," Coleman told reporters. Woodside will now return to its joint venture partners, which include BP, Japanese consortium Mitsubishi and Mitsui, and PetroChina, to recommend exploration of alternative development models including a floating LNG plant. Coleman said Woodside supported the floating concept but it had "no preference yet" for options, warning it would take between two and five years to get back to the final investment decision stage. The project had faced significant opposition from environmental groups and local Aboriginal landholders, and the latest news was welcomed as a victory for wildlife and cultural sites. The decision was unveiled just months away from national elections, when the government's economic management and Australia's painful diversification away from mining is expected to come under scrutiny. Prime Minister Julia Gillard, who is lagging badly in the polls, was quick to assure voters that the decision was not an indication that the mining boom, which saw Australia dodge recession during the financial crisis, was at an end. "We haven't seen the peak of the investment phase into resources yet and we are yet to see the peak of the production phase," said Gillard, promising "decades and decades" of resources sales yet to come. Australia is set to become the world's biggest liquefied natural gas producer, with predictions it will overtake Qatar by 2020 as it unlocks reserves that could last more than a century. Analysts said Woodside had likely been spooked by cost blowouts and time delays at its other major LNG project, Pluto, north-west of Karratha. "(It) has had to learn a hard lesson that its onshore processing is a very costly business," said IG Markets analyst Evan Lucas. "The Browse development was looking like deja-vu. Several broker notes show the internal rates of return for Browse were well below viability levels and cash flows were not stacking up." The Broome Community No Gas Campaign said it "cautiously" welcomed the decision but would not rest until it was certain that James Price Point would remain untouched. "All the environmental, cultural and social reasons that we opposed the precinct remain," said campaign spokesman Nik Wevers. "Our opposition will not cease until we are sure that the James Price Point area -- the monsoon vine thickets, the dinosaur footprints and the cultural heritage sites -- are all protected." Australia has three operating LNG plants and seven others under construction, with projects worth about Aus$200 billion on the drawing board, according to the nation's Petroleum Production and Exploration Association.