Shares of JetBlue Airways Corp. (JBLU - Get Report) took off Thursday after the airline announced quarterly results that surpassed analysts' expectations.

Excluding special items, JetBlue earned $155 million, or 55 cents a share, in the fourth quarter, up from $103 million, or 32 cents, in the year-earlier period. Analysts surveyed by FactSet had expected the airline to report earnings of 43 cents a share.

For the full year, the company earned $487 million, or $1.56 a share, vs. $574 million, or $1.74 a diluted share, in 2017.

Shares of JetBlue jumped 5.1% to close at $18.12 in Thursday trading on the Nasdaq Stock Exchange.

Fourth-quarter 2018 results benefited from solid non-fuel cost control and revenue performance through the quarter, the company said in a statement. For the first quarter of 2019, capacity is expected to increase between 7.5% and 9.5% year over year.

"We expect 2019 will be a stepping stone year to deliver on our 2020 goals, and to further improvements beyond 2020," Chief Operating Officer Joanna Geraghty said in a statement. "We expect to see margin expansion resulting from our network reallocation, ancillary revenue initiatives, improvements to our fleet and our progress in better controlling our costs.

"We remain confident in our ability to execute on our building blocks and achieve our $2.50 to $3.00 earnings-per-share target in 2020," she said.