Nov 9 (Reuters) - Cotton prices in India are likely to rise this week before easing off as arrivals, on account of delayed harvesting, could build up to a surge in coming days, traders said.

Cotton arrivals in Indian spot markets fell 30 percent in October as unseasonal rains delayed harvesting of the crop, an official at the state-run Cotton Corp of India said on Tuesday.

"Fresh supplies have started in the market but it is below last year's levels. Harvesting is still going on at many places and till the supply pressure builds up, prices are expected to rise," said Arun Kumar, a trader based in Ahmedabad in Gujarat, the largest grower of the fibre.

Traders expect cotton prices to rise this week before easing as arrivals from the fresh crop increase. The peak arrival season in cotton is Nov-Dec.

India's biggest customer for cotton is China and it is also a key supplier of the fibre to neighbouring Pakistan and Bangladesh.

China could boost imports over 22 percent in the year to July 31, 2012, the International Cotton Advisory Committee said on Monday.

On Tuesday, the most traded Shankar-6 variety fell 1,000 rupees to 37,500 rupees per candy, data from the trade body Cotton Association of India showed.

By Wednesday afternoon prices had recovered by 100-200 rupees to 37,600-37,700 rupees per candy, traders said.

Prices in India had hit a record high of 61,700 rupees per candy in March, tracking global prices CTc1 that rose to an all-time high of $2.27 per lb as adverse weather conditions in key growing areas disrupted the supplies.

India extended unrestricted cotton exports in the new marketing year after a sharp fall in prices in both domestic and overseas markets and increased supply view on projected record harvest in 2011/12 season.

The state-run Cotton Advisory Board (CAB) expects India to harvest 35.5 million bales of 170 kg each in 2011/12 season, a record high for the second consecutive year as farmers, lured by high prices, planted the crop in more area.