The European Commission may propose that a minimum number of emission allowances for power plants and factories be auctioned rather than allocated for free.

The measure would be part of new EU emissions-trading rules beginning in 2013 that the commission now intends to present on 23 January instead of 5 Dec as originally planned.

"Auctioning makes sense because you have to pay for pollution, " commission environment spokeswoman Barbara Helfferich said in Brussels. "Nobody should really be allowed to pollute for free.'" The commission, the EU's regulatory arm, is drafting rules to meet the bloc's 2020 goals of reducing greenhouse-gas emissions by 20 % and increasing the market share of renewable energies such as wind power to 20%.

The package will need the support of national governments and the European Parliament in a process that can take two years or longer.

The EU is trying to keep alive the idea of binding emission limits in any global treaty to succeed the Kyoto Protocol amid warnings about climatechange disasters.

Gases such as carbon dioxide are blamed for higher world temperatures, rising sea levels and more frequent heat waves, storms and floods. The package due in late January will include proposals for what individual EU nations must do for the 27nation bloc to meet its 2020 emissions-reduction and renewable-energy targets.

The package will also have proposals for post-2012 emissions-trading changes including possibly adding more industries . . . the EU already plans to add airlines as soon as 2010 . . . and of pollutants other than carbon dioxide.

"It's a complex package, " Helfferich said. "There are a lot of technical issues that still need to be coordinated."