Turkey's benchmark index started with a 199.51-point or 0.20 percent decrease to open at 99,439.14 points on Wednesday.
On the first trading day of the week, the banking sector index slipped 0.24 percent while the holding index was flat.
Among all sectors, the mining sector index was the best performer with a 1.05 percent rise, while the telecommunication sector index started the day with the biggest decline, falling by 1.62 percent.
At the close on Friday, the BIST 100 was also down 433.50 points or 0.43 percent to reach 99,638.65 points, with a total trading volume of 3.3 billion Turkish liras (approximately $941 million).
The U.S. dollar/Turkish lira exchange rate rose to 3.5210 at 9.30 a.m. local time (0630GMT) Wednesday, compared with 3.5080 at Friday’s close.
