Russian Prime Minister Vladimir Putin and European Commission Chief Jose Manuel Barroso came into a conflict Thursday over a latest EU energy legislation which could hit Russian oil industries.

In a press conference held in the middle of Putin's visit to the EU headquarters, the Russian prime minister said changes to the EU energy law, which stops oil and gas suppliers from managing pipelines, amounts to "property confiscation"and could hurt Russian enterprises.

At the core of Thursday's clash is a change to the EU law aimed to boost competition in the European gas market to prevent one company from controlling the entire supply chain in a country, thus bring down prices.

The latest introduction of a "reciprocity'clause to the law requires non-EU countries and companies to comply before operating in the EU.

In what he described as a "frank" exchange of views, Putin warned "full implementation of the package will lead to an increase of energy resources prices in the European market."

His host Barroso, however, countered that the legislation was "nondiscriminatory," and that the rule applied to both Russian and European companies."I understand the concerns expressed so clearly, so energetically," Barraso said.

The European Commission chief also ruled out any changes, saying "this is now approved legislation."

Russia is the EU's most important single supplier of energy products, accounting for over a quarter of the bloc's consumption of oil and gas.

At a Feb. 4 EU summit, European leaders launched a trillion- euro bid to slash dependency on Middle East oil and Russian gas, by linking national and regional electricity grids and gas pipelines by 2014 to allow power to circulate freely and cheaply.