India's infrastructure sector grew 4.2 per cent year-on-year in December, after expanding by just 3.3 per cent the previous month, boosted by robust expansion by the cement and steel sectors, data showed on Wednesday.

The infrastructure sector, which spans the six core sectors of electricity, coal, steel, crude oil, refinery and cement, grew 5.1 per cent in December 2001.

The core sector grew 5.4 per cent year-on-year in the first nine months of 2002-03 (April-March), compared with a growth of 2.5 per cent in the corresponding period the previous year, according to government data.

But analysts said fears of a US-led attack on Iraq, which have driven global oil prices higher, could hurt growth in the short term.

The infrastructure sector is crucial as it accounts for more than a quarter of India's industrial output and is considered to be an advance indicator of the country's industrial growth.

India's industrial output growth slowed to 3.7 per cent year-on-year in November -- from 6.2 per cent in October, as the impact of a drought on the farm sector began to hurt demand.

The cement sector, which has fuelled growth in previous months, grew 16.2 per cent in December, compared with a rise of 13.2 per cent in the same month in 2001.

The steel sector grew 7.5 per cent in December, against 7.4 per cent the preceding year.

The laggard was the electricity sector, which has a near 40 per cent weightage in the infrastructure index. It grew 2.5 per cent in December, compared with 4.1 per cent in the year-ago period.

The petroleum refining sector shrunk 7.1 per cent in December, compared with the growth of 9.1 per cent in the same month of 2001, while the crude oil sector grew 1.2 per cent, after contracting 1.2 percent in the same month the preceding year.