The company said in a statement the two sides signed a revised deal for a five-year extension, estimated to be worth 381.15 billion won ($336 million).

KAI won the $600 million deal in late 2011 to provide wing components to the Airbus by 2025, a company spokesman said.

KAI's net profit jumped 49 percent to 268.11 billion won in 2016 from 180.57 billion won a year earlier, helped by increased export deals and local supplies.

Operating profit rose 10 percent to 314.96 billion won from 285.66 billion won during the same period. Sales were up 6.9 percent to 3.101 trillion won from 2.901 trillion won. 

In earnings forecasts for this year, however, the aircraft company said it expects to earn 230 billion won in annual net profit while putting operating profit at 340.1 billion won on sales of 3.4 trillion won.

"We lowered the net income figure for this year as we expect higher one-off costs such as increased interest for our borrowings," the spokesman said.