* CEO criticizes government delay in reviewing project * HidroAysen seeks to provide 2,750 megawatts * Patagonia project criticized on environmental grounds SANTIAGO, Jan 12 (Reuters) - The mega HidroAysen hydropower complex's first plant will not be ready before 2022, four years later than previously planned, due to a Chilean ministerial group's "delay" in reviewing the controversial project, HidroAysen's CEO was quoted as saying on Saturday. Uncertainty surrounding the 2,750 megawatt, $3.2 billion investment also means its planned transmission line probably won't be submitted for environmental approval this year, Daniel Fernandez told local newspaper La Tercera. "Today, there's a lot of uncertainty, we don't have the conditions to present (the transmission line)," Fernandez was quoted as saying. "In the original program, we were meant to have started works already. We're not doing it because without a transmission line we're not going to take the risk. The first plant was planned for 2018, and today it is hard for it to be ready before 2022." The complex planned in pristine Patagonia has faced stiff opposition by environmentalists who have brought it to a special ministerial group to be reviewed. Opponents have slammed the project for its plans to flood large swaths of unspoiled land and have charged it will hurt the environment and tourism. The joint venture between leading generator Endesa Chile and partner Colbun is seen as key source of future energy supply in world No.1 copper producer Chile, whose power production has been hit by underinvestment, unclear regulations and droughts. The entire HidroAysen complex had been expected to be operational by 2025. Uncertainty over Chile's plans to build a public transmission line have also led HidroAysen to slow work on its own transmission projects as it awaits further clarity on the government's project, Fernandez said. Chile is failing to take a firm hand in regulating its mining and energy industries, leaving billions of dollars' worth of projects exposed to the risk of lawsuits by local communities. The government faces mass protests as Chileans demand a bigger share of copper earnings, and some critics charge that a regulatory vacuum has emerged, allowing opposition groups to jeopardize approved plans for hydropower projects in the South, thermoelectric plants across the country and major copper mines high in the Andes. "What we want is for once and for all that the project be seen as a priority, that complaints be resolved, so that we know how to go forth with the project," Fernandez added. "The system so far hasn't become more vulnerable, but if there are droughts, or if the transmission line issues become very hot, or if a plant collapses, then we're going to have vulnerability in the system, potentially (power) cuts, and any expert can tell you that 2016 is the crisis point," he said.