European Union regulators are open to a settlement with e-book publishers owned by Lagardere, News Corp and three other firms if they offer concessions to resolve competition concerns, the EU's antitrust chief said today.

Since last December, the European Commission has been investigating whether the publishers fixed prices with Apple for electronic books, an action that might have blocked rivals such as Amazon and hurt consumers.

Lagardere's Hachette Livre unit and News Corp's Harper Collins are being investigated. The other three publishers are CBS Corp's Simon & Schuster, Pearson's Penguin and Verlagsgruppe Georg von Holzbrinck, which owns Macmillan in Germany.

"This possibility of a settlement is only open in the case the publishers will be ready to remove all our objections," European commissioner for competition Joaquin Almunia told reporters.

He said EU regulators were co-ordinating with US counterparts, which are also looking into such pricing deals under an agency model adopted in 2010 in which publishers set the retail price.

Under the Commission's settlement procedures, companies could offer concessions to avert a fine of up to 10 per cent of their global sales. Regulators would then drop their investigation without the companies admitting to any wrongdoing.

US regulators have warned Apple and the five publishers that it plans to sue them, a person familiar with the matter told Reuters last week. The person also said several of the companies were holding talks to settle the case.

The wholesale model used by Amazon allows retailers to pay for the product and charge what they like.