* Three link up to speed up large-scale market launch * Other carmakers such as Renault invited to join * Alliance aims to build six-digit number of fuel cell cars By Christiaan Hetzner NABERN, Germany, Jan 28 (Reuters) - Daimler, Ford and Nissan plan to develop and launch affordable fuel-cell vehicles within five years, in the latest sign of increasing cooperation among automakers to meet ever-tighter global emissions rules. Mercedes-Benz parent Daimler, whose hydrogen-powered car technologies are the most advanced but still prohibitively expensive, will pool investment with its Japanese and U.S. partners under a contract announced on Monday. The programme aims to cut the technology's costs and launch the world's first fuel-cell vehicles for the mass market in 2017, the companies said. "We are firing the starting gun with this deal," Daimler development chief Thomas Weber told reporters in Nabern, home to the company's fuel-cell programme. Combined sales volumes for the new models would reach six figures, he predicted. By spreading development costs - and using Ford and Nissan's sales volumes to help cover them - Daimler is giving up some of its lead on the technology for faster implementation and a stronger business model. The three-way deal follows a similar announcement by Toyota and BMW, which outlined plans last week to launch fuel-cell vehicles around 2020. Pure-electric cars are struggling to gain a foothold even in markets where they get generous subsidies, so manufacturers are looking for other ways to meet emissions limits in China, Europe and the United States. Hybrid vehicles, which combine a combustion engine with an electric motor and rechargeable battery, are gaining ground but will struggle to deliver the fuel efficiency needed to meet the next wave of regulations coming into force in 2020-25. Fuel-cell cars, in common with rechargeable models like Nissan's Leaf, are propelled by electric motors. But instead of a battery, a "stack" of cells combines hydrogen with oxygen from the air to generate the electricity. This means fuel-cell cars largely avoid the "range anxiety" weighing on electric cars. They can fill up in minutes at a hydrogen pump and drive several times the typical 160-kilometre range of a battery car, which needs anything from 30 minutes to eight hours to recharge. INFRASTRUCTURE NEEDED The three carmakers said their plan sent a signal to suppliers, governments and broader industry to go ahead with infrastructure investment in hydrogen filling stations. Keen to get the ball rolling in its home market, Daimler has joined with industrial gas producer Linde to install 20 hydrogen filling stations in Germany. Fuel cells face a chicken-and-egg problem that has also blighted electric cars: buyers remain wary until a refuelling network is rolled out, but infrastructure investors are waiting for the vehicles to become widespread first. Current manufacturing costs for the vehicles themselves are still more than twice those of equivalent lithium-ion battery models - but may come down much faster, some analysts say. "Lithium-ion batteries are not the silver bullet everyone thought - just look at Boeing and the Dreamliner," said IHS Automotive analyst Christoph Stuermer, referring to electrical problems that have grounded the U.S. planemaker's flagship jet. "People are realising they can't put all their eggs in one basket," he said. South Korean group Hyundai has said it expects to halve production costs for fuel-cell cars to 50 million won ($46,000). Monday's announcement upgrades Daimler's existing fuel-cell research venture with Ford and brings in Nissan. The German luxury carmaker entered a broad-based strategic alliance with Nissan and its French affiliate Renault in 2010. While Mercedes has been at the forefront of fuel-cell research, German rival BMW had initially backed a rival liquid hydrogen technology. Under last week's deal, BMW gains access to Toyota's fuel cells in exchange for some of its own carbon-fibre know-how. General Motors Co has made more progress on fuel cells than Daimler or Toyota, GM Chief Executive Dan Akerson said on Monday, but the U.S. carmaker is holding back until refuelling networks are rolled out and the technology is less costly. "None of them are as far along as we are," Akerson told reporters after announcing a $600 million investment in GM's Kansas City, Kansas, assembly plant. "But we're not going to press this thing into the marketplace before the infrastructure is ready." Hyundai is also betting on fuel cells to leapfrog battery technology and showed hydrogen-powered production models at last September's Paris auto show. As Daimler and many peers are increasingly convinced, hydrogen cars now offer "the greatest potential for emission-free driving," Weber said.