Oct 30 (Reuters) - Brazilian brewer Ambev ABEV3.SA posted on Thursday a third-quarter net profit of 4.86 billion reais ($899.35 million), up 36.4% from a year earlier and above the 3.19 billion reais expected by analysts polled by LSEG.
The company also said in a securities filing its board of directors approved a new share buyback program, aiming to purchase up to 208 million shares - or about 2.5 billion reais, based on its Wednesday closing price - within 18 months.
($1 = 5.4039 reais)
(Reporting by Tiago Brandao; Writing by Isabel Teles; Editing by Gabriel Araujo)
((Isabel.Teles@thomsonreuters.com;))