BRUSSELS, July 25 (Reuters) - Meta Platforms (META.O) offered to curb the use of competitors' advertising data for its Facebook Marketplace online classified service in an attempt to settle an EU antitrust investigation but regulators gave it the cold shoulder, people familiar with the matter said.

Its offer also included limiting the use of advertising data to develop products that compete with advertisers, the people said.

Meta's proposal, similar to one made to the UK competition agency in May, suggests that the company will have to do more to counter the EU watchdog's charges if it wants to stave off a possible fine.

However, the sources said Meta was not expected to improve its offer. The UK enforcer in a preliminary view has said Meta's offer addresses its concerns.

Companies risk fines of as much as 10% of their global turnover for EU antitrust violations.

The world's most popular social network sought to settle the EU investigation opened in June last year, other people familiar with the matter told Reuters last December. Details of Meta's proposed concessions had not been previously reported on.

Both the European Commission and Meta declined to comment.

The EU antitrust watchdog last December charged Meta with abusing its market power through two practices, one of which was tying its online classified ads service Facebook Marketplace with its social network Facebook.

The other was allegedly its unfair trading conditions imposed on rival online classified ads services which advertise on Facebook or Instagram. Meta contested the EU charges at a closed hearing earlier this month.

Reporting by Foo Yun Chee; Editing by Susan Fenton