HSBC is set to agree to sell its Turkish business to Dutch lender ING Group for around $700-$750 million in the next few days, two people familiar with the matter told Reuters.

ING, which already has a presence in Turkey, was one of three banks to submit a non-binding bid in May, sources previously told Reuters. The others were Bahrain's Arab Banking Corp and France's BNP Paribas. HSBC declined to comment.

Meanwhile, İstanbul's main stock index Borsa İstanbul fell 1.1 percent as violence in Turkey's southeast near the Syrian border heightened investor worries about security.