ROME, March 22 (Reuters) - Abu Dhabi's investment firm Aabar is the top investor in UniCredit CRDI.MI with a stake of 5.04 percent after the Italian bank raised 13 billion euros in a share sale earlier this year, the lender's website showed on Wednesday.

Prior to the share issue, UniCredit's top shareholder was Los Angeles-based fund Capital Research and Management Company with a stake of 6.7 percent.

Italian press had reported Capital Research had boosted its position as top investor by buying into the cash call. However, a regulatory filing dated Feb. 28 showed the U.S. fund had cut its stake to 4 percent outside of the cash call.

Investors are obliged to disclose significant holdings, but sometimes do not provide frequent updates.

(Reporting by Valentina Za, editing by Isla Binnie) ((valentina.za@thomsonreuters.com; +39 02 6612 9526))