E.ON AG (EOAN.XE) has secured itself the right to reclaim nuclear power production quotas the German utility sold to its main domestic competitor RWE AG (RWE.XE) over the weekend, said Chief Executive Johannes Teyssen Tuesday.

"We have the right to reclaim the same power production quota if we consider this economically and strategically reasonable," Teyssen told journalists in a conference call.

On Sunday, E.ON and RWE said they agreed to transfer power production quotas from E.ON's decommissioned Stade nuclear power plant to the Biblis A reactor, which would allow RWE to operate Biblis A longer.

A press report last week said that RWE would pay E.ON a three-digit million euro amount for the transfer of around 4.8 terrawatt-hours of the Stade power quota to Biblis A.

Teyssen Tuesday declined to disclose the financial details of the transaction.

In a conference call to analysts Teyssen added that the "financial impact of the transaction is limited".

The deal would allow RWE to operate Biblis A longer than is currently legal under
Germany 's existing nuclear phase-out laws.

Under the laws, all of the country's remaining 17 nuclear plants will have to be shut down by around 2022. Biblis A is the country's oldest operating reactor and would be one of the next nuclear power plants to be shut down.

Chancellor Angela Merkel's government, however, has pledged to postpone the nuclear phase-out to help the country achieve ambitious climate change targets. The government plans to present an energy roadmap this autumn, which is expected to include details about a possible postponement of the nuclear exit.

The reactor Isar 1 is the next E.ON-operated nuclear power plant that will have to be shut down. At the beginning of 2010 the reactor had a remaining quota that would allow it to produce a further 9.9 TWh. Under constant operation at full capacity the 878-megawatt reactor would have to be shut down by around the middle of 2011.