BRUSSELS, Jan 31 (Reuters) - EU antitrust regulators opened on Monday an investigation into fashion house Pierre Cardin's licensing and distribution deals with German clothing maker Ahlers, concerned that these may breach EU rules on online and cross-border sales.

"Pierre Cardin and Ahlers may have breached EU competition rules by restricting the ability of Pierre Cardin's licensees to sell Pierre Cardin-licensed products crossborder, including offline and online, as well as to specific customer groups," the European Commission said in a statement. (Reporting by Foo Yun Chee)