United Continental announced a $3 billion buyback program after the market close Thursday.
Shares of the airline operator gained more than 1 percent in after-hours trade.
The company said in a statement that this amount represents about 17 percent of its market value as of its Wednesday closing price.
CFO Andrew Levy said in a statement that the share repurchase program "reflects the strength of our balance sheet and the confidence we have in our future."
In July 2016, United approved a $2 billion buyback program, which the company expects to close by the end of the year.
As of their Thursday close, United shares have declined more than 12 percent so far this year.
Correction: This story has been updated to reflect that United's $2 billion buyback was announced in July 2016.