Industrial output in Turkey fell 4% year-on-year to 110.9 in April, according to the country's statistical authority on Tuesday.
Among three main sub-indices, electricity, gas, steam and air conditioning supply index was the sole sector on rise, increasing 0.7% during the same period, TurkStat said.
Mining and quarrying, and manufacturing indices decreased 9.3% and 4.2% on an annual basis in the month.
Industrial production is considered a vital indicator for the economy, as it is seen as a preliminary gauge for gross domestic development (GDP) growth.
The production level was also lower than the same figure for March.
"Industrial production [in April] decreased by 1% compared with the previous month," TurkStat said in a statement.
On a monthly basis, electricity, gas, steam and air conditioning supply index rose by 1.9% in April.
The manufacturing index fell 7.8%, while the electricity, gas, steam and air conditioning supply index saw a decrease of 0.9% in the same period.
By Tuba Sahin