India and Sri Lanka are seeking a broad economic deal to free up services such as tourism and aviation and pave the way towards possibly sharing electricity, officials from both the countries said on Tuesday.

Economic ties between the South Asian countries are gradually improving as Sri Lanka looks to end a 20-year ethnic war with Tamil rebels that also strained relations with its giant neighbour.

Officials said plans for sharing electricity were likely to be in the distant future.

An economic partnership agreement could be in place within a couple of years -- the same time it took to hammer out a free-trade pact that has had some success, said V Ashok, the economic and commercial counsellor at the Indian High Commission in Colombo.

"It could be a similar timeframe or shorter," he said.

A Sri Lankan official who will be involved in the discussions said they will be wide-ranging.

"The subjects are likely to be tourism, infrastructure, ports, railways, currency convertibility, air travel and education," he said.

India is the largest exporter to Sri Lanka and sells everything from sugar and medicine to tuk-tuks (Bangkok-style three-wheelers) and diesel fuel.

Last year, Sri Lanka exported mainly copper wire to India in total exports worth about five times less.

The Sri Lankan official said the agreement, modelled along the lines of a pact India is planning to seal with Singapore to boost trade and services, would allow for closer links in the long run.

He said Sri Lanka could aim to obtain power from India in the future as a nuclear power plant was being built in South India, although the infrastructure needed to ship power across the Indian Ocean was not in place.

Indian investment in Sri Lanka has improved with Indian Oil Corp, India's largest crude refiner, buying petrol stations and leasing fuel storge tanks.