The European Union's executive commission voiced "concern" Wednesday over measures taken by the Bank of Italy that could prevent Dutch bank ABM Amro from raising its stake in Italian takeover target Banca Antonveneta above 20 percent.

"The commission is concerned that possibly some of the measures taken by the Bank of Italy may in some way or other interfere with the pursuit of this particular concentration," said commission spokesman for competition issues, Jonathan Todd.

ABN Amro is currently in a bidding war with Italian rival Banca Popolare di Lodi to take over Banca Antonveneta.

The commission's competition directorate-general was concerned that the Bank of Italy had told ABN Amro it could not raise its stake in Antonveneta above 20 percent, Todd said.

Brussels had written to the Bank of Italy asking for clarification of its handling of ABN Amro's bid for Banca Antonveneta and was expecting an answer by May 4.

"In the light of info that we expect to receive from the Bank of Italy the commission will decide if there has been any violation of the merger regulations," Todd said.

He explained that under EU rules only the commission had "sole jurisdiction" to rule on mergers on a EU scale unless "prudential" measures could be justified by the parties involved.

In 1999, the commission used its powers to take the Portuguese government to task over Lisbon's decision to block a proposed alliance between Spain's Banco Santander Central Hispanico and Portugal's Champalimaud.