Turkey's stock exchange fell 0.13 percent, or 134.14 points, to open at 104,979.24 points on Wednesday.
Among all sector indices, the sports index posted the best performance, up 1.24 percent, while the chemicals petrol plastic index saw the worst, down 0.47 percent.
The BIST banking indices decreased by 0.06 percent.
On Tuesday, Borsa Istanbul's BIST 100 index closed at 105,113.38, down 1.33 percent, with a 6.5 billion-Turkish lira ($1.42 billion) trade volume.
The U.S. dollar/Turkish lira exchange rate decreased to 4.5410 as of 9.30 a.m. local time (0630GMT) on Wednesday. It was 4.5790 at Tuesday's close.
The euro/lira exchange rate decreased to 5.2550, compared with Tuesday's close of 5.3050.
The price of Brent oil was $75.44 per barrel as of 10 a.m. local time (0700GMT) Wednesday.