SINGAPORE (Reuters) - Singapore's annual industrial production is expected to have declined in March, a Reuters poll showed, though output is seen rising month-on-month with some optimism that signs of improving exports will underpin a struggling manufacturing sector.

The median estimate in the survey of 14 economists was for industrial output in March to fall 5.9 per cent on-year, mainly reflecting a high-base in the year-ago period.

In March 2014, manufacturing output had surged 12.2 per cent year-on-year, buoyed by sharp expansions in pharmaceuticals production as well as marine and offshore engineering output.

On a seasonally adjusted month-on-month basis, manufacturing output was seen rising 0.5 percent.

One reason for optimism was a surge in exports, which rose 18.5 per cent in March from a year earlier, the biggest increase in three years.

A recent survey of purchasing managers, however, showed that Singapore's manufacturing activity hit a three-month low in March, contracting for a fourth consecutive month, as new orders declined.

Singapore's central bank said last week that the city-state's economy was on track to meet the official forecast of 2-4 per cent growth in 2015.

The Monetary Authority of Singapore, which surprised markets by holding off from further monetary easing at its policy review on April 14, said an improving outlook for global growth would underpin the trade-reliant economy.