By Foo Yun Chee

BRUSSELS (Reuters) - CK Hutchison Holdings has offered to strengthen rivals such as Swisscom's Fastweb in return for EU antitrust approval for its plan to merge its Italian mobile business with that of Vimpelcom, a person familiar with the matter said on Tuesday.

The European Commission said on Tuesday that Hutchison has offered concessions in a bid for EU approval of the deal. Hutchison, controlled by Asia's richest man, Li Ka-shing, put in its proposal on Monday, according to a filing on the commission's website, without providing details.

Hutchison had no immediate comment.

According to the person familiar with the matter, Hutchison is prepared to give some spectrum, equipment and roaming deals to create a fourth network operator in Italy.

Italian telecoms provider Fastweb is one of several bidders for Hutchison's assets, the source said.

That would help address the commission's concerns about Hutchison's Vimpelcom deal, which would reduce the number of Italian network operators from four to three.

Such worries prompted the EU competition authority to veto Hutchison's bid to acquire British mobile operator O2 from Spanish provider Telefonica last month after Hutchison failed to form a UK fourth network operator. The commission is likely to seek feedback from interested parties as soon as Wednesday before deciding whether to accept the offer, the person said.

(Reporting by Foo Yun Chee; Editing by Leslie Adler)