The measure was proposed during talks with representatives of the International Monetary Fund, said Liviu Voinea, a secretary of state with the ministry.

He said the new tax will be charged for the duration of the deregulation process and will be implemented as of next year, pending consultations with the relevant companies and with officials of the IMF and the European Union.

“It won’t be a tax on profit, because profits can be hidden. Instead, it will be a tax on additional revenues,” Voinea said.

The tax will be calculated based on the new prices charged by producers for the electricity and gas sold on the free market, minus a fixed reference price established by the Romanian regulatory authority, Voinea said. The result will then be multiplied by the volumes sold and by a percentage which is yet to be set, he added.

The new tax is expected to bring additional revenues to the state budget of hundreds of millions lei, Voinea said.

Under a EUR5 billion IMF/EU loan program, Romania pledged to deregulate electricity and gas tariffs for both households and industrial consumers. The authorities have already approved a 5% increase in electricity tariffs starting with July.

IMF’s mission chief to Romania, Erik de Vrijer, said earlier Tuesday that the government has agreed to increase gas prices by 5% for households and by 10% for corporate customers as of September.

The measure will compensate for higher production costs registered over the past years and does not modify the country’s official calendar for price deregulation, de Vrijer said.

Romania’s initial calendar for gas price liberalization stipulated gas tariffs were to remain at their existent levels until 2013.