June 19 - EU antitrust regulators have set a July 23 deadline for their ruling on French aerospace and defence group Thales's 4.8 billion euro ($5.5 billion) bid for Franco-Dutch chipmaker Gemalto, the European Commission said on Tuesday.

Thales, Europe's largest defence electronics group, sought EU approval on June 18, according to a filing on the EU competition enforcer's site.

The Commission can nod through the deal with or without concessions or open a four-month investigation if it has serious concerns.

Thales, which beat off a competing bid from French rival Atos for Gemalto, is looking to expand in the fast-growing digital security market via the acquisition. The combined company would be one of the top three players in digital security.

The French state is the largest shareholder in Thales while state-owned bank Bpifrance is Gemalto's second-biggest shareholder.

($1 = 0.8660 euros)

(Reporting by Foo Yun Chee, editing by Louise Heavens) ((foo.yunchee@thomsonreuters.com)(+32 2 287 6844)(Reuters Messaging: foo.yunchee.thomsonreuters.com@reuters.net))