* Coal imports seen rising further amid fears ban may expand
* Cement firms scrambling for U.S. coal - executive
* Petcoke ban in and around New Delhi in place from Nov. 1 (Recasts first two paragraphs to show alternative import estimates)
NEW DELHI, Nov 20 (Reuters) - India's coal imports from North America are likely to surge as buyers are looking to boost purchases amid a domestic shortage of the fuel and a regional ban on petroleum coke, traders and cement company officials said.
Shipping data from Thomson Reuters showed that India's coal imports from North America tripled to 2.1 million tonnes in October from a year ago. Other trading sources put this figure lower, at 1.47 million tonnes, and they said coal imports for Nov. 1-20 have reached 1.14 million tonnes.
Indian imports of North American coal, including supplies from Canada, stand at about 1.5 million tonnes from Nov. 1 to 20, Thomson Reuters data showed, already more than 70 percent of last month's purchases.
A ban on the use of petroleum coke, a dirtier but better-burning alternative to coal, is spurring expectations India will buy even more coal from the United States in coming months.
Petcoke has been banned in some states around the Indian capital New Delhi which is battling heavy smog.
But rising pollution in other Indian cities could lead to tougher restrictions such as a nationwide ban on use and imports of petcoke, with environmentalists requesting other states in the country to consider banning the use and import of the dirty fuel.
"Every cement company is looking for an alternative to petroleum coke, and all of them are scrambling for U.S. coal," a senior executive from one of India's top three cement companies told Reuters.
The executive had sold 70,000 tonnes of U.S. coal to a client, of which the client had paid for 30,000 tonnes. But the executive said he later took back the 40,000 tonnes that was still unpaid, after realising his own company might need it.
Cement companies account for nearly 75 percent of India's annual petcoke demand of 27 million tonnes, according to trade data, and small industries such as lime manufacturers are also considering the use of U.S. coal, which is almost as efficient as petcoke.
A tonne of 6,900 kcal/kg U.S. coal now costs up to 8,200-8,300 rupees ($126-$128) on online coal marketplace CoalShastra, up from 7,100-7,200 rupees two weeks ago, said its founder Puneet Gupta.
The petcoke ban may deter Prime Minister Narendra Modi's plan to cut India's coal imports, which have risen for the first time in the past two months after falling in the past few years.
($1 = 65.1000 Indian rupees) (Reporting by Sudarshan Varadhan; Editing by Manolo Serapio Jr.)