June's on-year industrial production print was the worst since December 2015 when it fell 11.9%, according to official data.
On a seasonally-adjusted and month-on-month basis, industrial production rose 1.2% in June, after a revised 0.1% fall in May. The median forecast was for a fall of 0.7%.
Electronics output further contracted in June at 18.8% from a year earlier after declining 10.8% in May.
The slump, in a sector that accounted for nearly a third of Singapore's manufacturing output last year, has cost hundreds of jobs and is adding to fears that the export-driven economy could slide into recession in the coming months.
Singapore's economy grew at its slowest annual pace in a decade in the second quarter, preliminary data showed, raising bets that a monetary policy easing could be around the corner.
The slump in the city-state, often seen as a bellwether for the health of the global economy, is the latest evidence that momentum has slowed across Asia, as the protracted trade war between the United States and China, and sliding growth weigh on the region's export-reliant economies.
