UPDATE 2-Third phase of EU carbon trading to go through 2020

(Adds Gabriel, backgound on Bali talks)

By Jeff Mason

LUXEMBOURG, Oct 30 (Reuters) - The third phase of the European Union's emissions trading scheme will run from 2013 to 2020, an official said on Tuesday, as EU ministers prepared for a crucial round of international climate change talks.

The European Commission is working on a revision of the EU emissions trading system, including the possibility of adding gases and sectors that are not currently included.

Companies and traders are also anxious to know the time frame for the next trading period. A Commission official said phase three would go to 2020, conforming with EU goals to reduce greenhouse gas emissions by at least 20 percent by that year compared to 1990 levels.

"I think you can assume that," the Commission official told Reuters when asked whether the third phase would go to 2020.

Industry has long called for the EU to set longer trading periods so it has more clarity for long-term planning. The first phase of the scheme went from 2005-2007 and the second phase runs from 2008-2012.

The Commission's delayed proposals revising the scheme as well as legislation governing renewable energy use in the bloc are now slated to be published on Jan. 23, he told reporters on the sidelines of an EU environment ministers meeting.

The EU trading system sets limits on the amount of CO2 that power companies, oil refineries and other energy-intensive businesses may emit, allowing them to buy or sell carbon permits based on whether they overshoot or come beneath their targets.