Turkish Airlines is bidding to buy a majority stake in Istanbul’s second airport from Malaysia Airports Holdings Bhd, five people with the knowledge of the matter said.

Turk Hava Yollari AO, as the company is formally known, could buy 80 percent of Istanbul Sabiha Gokcen International Airport, also known as ISG, two of the people said, asking not to be named because the talks are private. Turkish Airlines offered 750 million euros ($870 million) for the stake, one of the people said.

Turkish Airlines didn’t immediately respond to requests for comment on the deal. Malaysia Airports declined comment.

Turkish Airlines shares rose as much as 3.3 percent and were up 2.8 percent as of 4:05 p.m. in Istanbul, while the benchmark index gained 1.6 percent. The shares are up 12 percent this year, compared with a 15 percent drop on the broader Turkish index.

If the deal goes through, it’d mark a change in strategy for Malaysia Airports. Chief Executive Officer Badlisham Ghazali said in May that the company was looking for a partner to buy a minority stake and that 10 parties were interested.

Malaysia Airports was part of a consortium that won a 1.9 billion euro ($2.2 billion) contract to operate the airport in 2007. In 2013, it agreed to raise its holding in ISG to 60 percent by acquiring a 40 percent stake held by Indian partner GMR Infrastructure Ltd. for 225 million euros. It bought the remaining 40 percent from Turkey’s Limak Holding in 2014 for 285 million euros.