India's industrial output grew just 0.1% in April year-on-year, adding to concerns about the economy and raising the chances of a rate cut next week.
The manufacturing sector, which accounts for three-quarters of the industrial production index, also expanded a weaker-than-expected 0.1%.
And production of capital goods, a key indicator of investment, shrank 16.3%.
The data adds to an increasingly gloomy picture of the once-booming Indian economy.
Analysts say the country has been hit by a lack of economic reforms, high interest rates, plummeting business confidence and the euro zone debt crisis.
They had expected industrial production to increase 1% in April, after a shock contraction of 3.5% in March. The new data comes on the heels of figures published on May 31 showing the Indian economy expanded 5.3% in the January-March period, the slowest quarterly growth figure in nine years that led to a round of soul-searching.
After a decade of scorching near double-digit economic growth, there is growing alarm that India is sliding back towards its previous expansion rate of 5-6%.
The government says India needs higher growth to lift its overwhelmingly poor 1.2-billion population out of poverty and provide the estimated 8-10 million new jobs every year to absorb the expected growth in the labour force.
In contrast to the woes in India's industrial sector, output from China's factories grew 9.3% in April on a 12-month basis and 9.6% in May, the government said at the weekend.
Next Monday, India's central bank holds a policy meeting where it is expected to cut interest rates again, having raised them 13 times between March 2010 and October 2011.
Lower interest rates are likely to result in higher inflation - already at 7% on an annual basis - because of India's poor infrastructure and other structural constraints, many analysts believe. But the government is also unable to stimulate the economy because of a gaping fiscal deficit and increasing pressure to rein in spending and subsidies.
The left-leaning administration of Prime Minister Manmohan Singh has also been unable or unwilling to push through economic reforms such as opening up the retail sector to foreign investment because of disagreements in the coalition.
Rating agency Standard & Poor's warned yesterday that India could be the first of the BRIC emerging economies to lose its investment-grade debt rating unless it revived its growth and rekindled its reform agenda.
In April, the firm downgraded India's credit outlook to negative from stable, maintaining its rating at "BBB-" but warning it faced at least a one-in-three chance of losing its status if its public finances worsened.
