Turkey's benchmark stock index slipped 0.49 percent or 463.33 points to open at 93,506.84 points on Thursday.
On Wednesday, Borsa Istanbul's BIST 100 index climbed 0.10 percent to close the day at 93,970.16 points with a daily trading volume of 6.08 billion Turkish liras ($1.13 billion).
The U.S. dollar/Turkish lira exchange rate rose to 5.3770 as of 9.30 a.m. local time (0630GMT), compared with Wednesday's closing rate of 5.3120.
The euro/lira rate was 6.1080, versus 6.0360 at the last close. One British pound traded for 6.8480 Turkish liras, as the GBP/TRY rate was 6.7970 by market close on Wednesday.
The price of Brent oil was $60.98 per barrel as of 10.00 a.m. local time (0700GMT) Thursday.