In a securities filing, Gol said earnings before interest and taxes, a gauge of operating profit known as EBIT, came in between 1.5 percent and 2 percent of net revenue, an increase of around 1,000 basis points from the year before, boosted by stronger revenues and lower fuel costs.
Analysts at UBS Securities led by Rogerio Araujo expected Gol's so-called EBIT margin of -2.1 percent, according to a Wednesday note to clients. The upside surprise drove them to forecast an 8.9 percent full-year EBIT margin, near the higher end of the company's 7 percent-9 percent guidance.
Preferred shares rose as much as 8.2 percent in morning trading, their biggest daily increase since late May. Brazil's benchmark Bovespa stock index <.BVSP> was down 0.7 percent on Wednesday.
Gol's profitability as measured by net passenger revenue per available seat-kilometre, or PRASK, rose between 7.5 percent and 8.0 percent, the filing said.
(Reporting by Ana Mano and Bruno Federowski; Editing by Jonathan Oatis)