The largest drop came in investment products, which include all kinds of machinery or equipment used in new investments.

Industrial output fell 17.4 percent from the same month last year, following a decline of 18.5 percent in April, the Ankara-based Turkish Statistical Institute, or TurkStat, said on its Web site on Wednesday. It was the 10th consecutive month that output in Turkey contracted.

According to a Bloomberg poll, analysts expected a decrease of 15.8 percent, while a Reuters poll showed an estimated 15.9 percent fall.

The scale of the contraction has shrunk from a record 23.8 percent in February, supporting Central Bank predictions that the fall in output would “stabilize” in the second quarter. Gross domestic product shrank 13.8 percent in the first three months, the biggest drop since quarterly records began in 1987.