China Petroleum and Chemical Corp (Sinopec) is looking to diversify its crude oil imports, the company's chairman said, following a sharp drop in its first-quarter purchases from Iran.

A contractual dispute between China's Unipec, the trading arm of Sinopec, and Iran's National Oil Company ended in February with a statement by the Chinese refiner that it was slashing its crude imports for 2012 by 10 to 20% from the previous year, depriving Tehran of as much as $2.4 billion in oil revenue.

"Sinopec has taken measures to diversify its imports. We have made a lot of efforts in terms of that," said Fu Chengyu, who took over the helm of the top Asian refiner about a year ago.

After more than two months of wrangling over price and credit terms between Unipec and Iran's NIOC, the dispute was resolved thanks in part to the intervention of Iranian Oil Minister Rostam Qasemi during a visit to Beijing last month.

"We further clarified some of the prices that previously had not yet been confirmed (during Qasemi's visit)," Fu said.

Data from Chinese customs released last week showed China's February crude imports from Iran, at some 290,000 barrels per day, had halved from the December level and were down 40 % versus January and year-earlier rates.

When asked whether Sinopec would cut its crude imports from Iran this year versus last, Fu did not comment directly but said, "there shouldn't be any major increase or decrease", as supplies were via a long-term contract.

The Chinese refiner, which supplies some 45 % of the fuel needs of the world's second-largest oil user, plans to process 3.5% more crude oil this year than in 2011, with crude throughput planned at around 4.5 million bpd.