SAO PAULO, Aug 10 (Reuters) - Brazilian investment holding Itaúsa, main shareholder in Itau Unibanco Holding SA is open to expanding its investment portfolio to renewable energy and agribusiness companies, Chief Executive Alfredo Setubal said.

The CEO told a press conference Itausa is considering investing in utilities other than water and sewage. Itausa is one of investors in Aegea, which recently acquired two of the four regions of Rio de Janeiro's water and sewage service in a privatization auction.

Itausa has invested 2.6 billion reais ($500 million) in Aegea.

Setubal expects a shareholder vote on the incorporation by digital broker XP Inc. of holding company XP Part. "XP is not an strategic asset to Itausa, but that does not mean we want to sell the stake," Setubal said.

He added that even if Itausa decides to divest, it will not be in an "abrupt matter."

($1 = 5.2031 reais) (Reporting by Aluísio Alves; Editing by David Gregorio)