BRUSSELS, May 23 (Reuters) - Lufthansa's bid to acquire a stake in Italian state-owned carrier ITA could lead to price hikes and fewer frequencies for passengers, EU antitrust chief Margrethe Vestager said on Thursday.

"It is for the emerging companies to set how to prevent this from happening. And this is the process that we're in right now," she told a news conference.

Vestager's comments underscore Lufthansa's uphill battle in securing her approval for the deal. Sources have told Reuters that she is poised to block the deal unless Lufthansa substantially improves its package of remedies offered earlier this month. (Reporting by Foo Yun Chee)