Turkey’s benchmark stock index, BIST 100, slipped 0.12 percent on Thursday to open at 109,611.68 points.
The banking sector index decreased by 0.36 while the holding sector rose 0.28 percent.
Among all sectors, the wood, paper, printing sector index was the best performer with a 0.35-percent rise, while the banking sector started the day with the biggest decline.
On Wednesday's close, the BIST 100 was up 0.68 percent to reach 109,611.79 points, with a total trading volume of 4.8 billion Turkish liras (nearly $1.4 billion).
The U.S. dollar/Turkish lira exchange rate fell to 3.4280 at 9.30 a.m. local time (0630GMT) Thursday, compared to 3.4340 at Wednesday's close.
Analysts said markets would focus on the European Central Bank's interest rate decision due on Thursday.
Investors are also expected to follow Eurozone GDP data for the second quarter of the year along with U.S. weekly jobless claims to be revealed in the day.