New Delhi: Headline inflation remained close to the double-digit mark at 9.72 percent in September as all items, including food products, fuel and manufactured goods, grew costlier, a development likely to prompt the Reserve Bank to continue with its policy of monetary tightening.

Inflation, as measured by the Wholesale Price Index (WPI), stood at 9.78 percent in August. The rate of price rise was recorded at 8.98 percent in September, 2010.

As per data released by the government on Friday, overall inflation in June this year was revised upward to 9.36 percent from the provisional estimate of 9.22 percent.

On an annual basis, food items became 9.23 percent more expensive during the month under review. Onions grew 23.58 percent costlier, while fruit prices were up 15.98 percent and the rates for potatoes rose by 14.64 percent.

Overall, vegetable prices witnessed 14.04 percent inflation during September, 2011.

Inflation in overall primary articles, which have a share of over 20 percent in the WPI basket, stood at 11.84 percent in September, compared to 12.58 percent in August.

Inflation in manufactured products has been steadily rising since February this year, when it crossed the 6 percent-mark.

Inflation in the fuel and power segment stood at 14.09 percent on an annual basis in September, as against 12.84 percent in August. Oil marketing companies had hiked petrol prices by over Rs 3 per litre in mid-September and this seems to have been reflected in the numbers.

This is the tenth consecutive month when headline inflation has been above the 9 percent-mark.

Elevated inflation levels close to double digits are likely to put pressure on the Reserve Bank to continue with its policy of monetary tightening, according to experts.

The apex bank has already hiked key policy rates 12 times since March, 2010, to tame inflation. The bank's next policy review is scheduled for October 25.

India Inc has said the string of rate hikes, which have raised the cost of borrowing, have acted as a dampener to fresh investment and hindered growth.

During the central bank's meeting at Jaipur earlier this week, RBI Governor D Subbarao had said the rate hikes have affected industrial activities, but asserted that inflation continues to remain above comfort levels. He also said that interest rates would come down only if inflation eased.