UPDATE 1-AGL revives major wind farm plan after policy change

* Final OK to build windfarm subject to legislative changes

* Macarthur wind farm to be built with Meridian Energy (Adds details)

PERTH, March 1 (Reuters) - Australia's largest energy retailer, AGL Energy Ltd (AGK.AX), revived plans to build a major wind farm on Monday, after the government vowed to increase investment security in the sector.

AGL said the Macarthur wind farm, previously estimated to cost A$800 million ($716 million), will be constructed in a joint venture with New Zealand's state-owned generator Meridian Energy Ltd [MEREN.UL], with AGL taking all of the wind farm's energy output and renewable energy certificates, it said in a statement.

AGL last week said it would shelve up to A$1 billion worth of planned investments in wind energy, citing uncertainty in the government's climate change policies. [ID:nSGE61O0O3]

Although Monday's statement signals a change in the company's plans, AGL added that final approval to build the Macarthur wind farm, located in the southeast state of Victoria, is subject to the government legislating the proposed changes to its renewable energy scheme.

Macarthur is expected to produce about 945 gigawatt hours of electricity a year and construction is expected to take about three years after getting the final go-ahead, AGL said.

The expected cost of the project will be updated at a later date, AGL said.

Shares in AGL rose 1.04 percent by 2340 GMT, outperforming a 0.37 percent gain in the broader index .AXJO.

Threats of major firms pulling the plug on some A$22 billion worth of renewable energy projects prompted the government to announce on Friday that it would reshape its troubled clean energy scheme, so that the market would no longer be flooded with cheap renewable energy certificates. (Reporting by Fayen Wong; Editing by Mark Bendeich and Balazs Koranyi)