NEW YORK (Reuters) - OPEC's full-year 2016 oil export revenues will probably fall 15 percent, down for the third straight year and possibly the lowest in more than a decade before rising in 2017, the U.S. Energy Information Administration (EIA) said on Wednesday.

Members of Organization of the Petroleum Exporting Countries (OPEC), including Iran, will likely earn about $341 billion in 2016, about 15 percent below 2015 levels, based on projections of global oil prices and the group's production levels, the U.S. government's EIA said in a report.

The last time OPEC's export revenues fell for three years straight was 1983-86.

At the projected level, OPEC's 2016 export earnings would be the lowest since 2004, when it earned about $295 billion

Early in 2016, oil prices touched 12-year lows before staging a recovery to about $50 a barrel over the last two months. After a long run of oversupply, the oil market is expected to return to balance, driven by output declines, making the forecast for 2017 less bleak.

Supply outages across the world, including Canada and Nigeria, have accelerated crude's price rebound.

For 2017, OPEC revenues are projected to be $427 billion, due to an expected increase in crude oil prices, higher OPEC production and stronger exports, EIA said.

The group earned about $404 billion in net oil export revenues for 2015, down 46 percent, the biggest drop since EIA began tracking the data in 1975.

In 2015, Brent crude <LCOc1> prices plummeted about 35 percent, or $20 a barrel, as major producers grappled with one of the worst gluts in history.

Attempts at a deal between OPEC and non-OPEC producers to shore up crude prices by freezing output fell apart this year when Saudi Arabia demanded that Iran, its main rival for influence in the region, join in.

In 2015, Saudi Arabia earned the largest share, about one third of total OPEC oil revenues or $130 billion.

The 2015 estimates included figures from Iran, unlike previous years, as sanctions against Tehran were lifted, but do not take into account price discounts it may have offered while these sanctions were in place, the EIA said.

Iran has explicitly said it had no plans to freeze the level of its oil production and exports, as the country tries to raise its crude exports to pre-sanctions levels.

EIA's estimates are not adjusted for inflation.

(Reporting by Devika Krishna Kumar in New York; Editing by David Gregorio)