Indian refiner MRPL secured coverage from an Iranian insurer for a crude cargo that arrived last week, becoming the first Indian firm known to have taken such action.
MRPL is buying oil on a free-on-board (FOB) basis with insurance covered by the Iranian firm.
India's insurers do not fall directly under the sanctions regime but depend on the Western reinsurance market to hedge their risk.
But an Iranian insurer provided cover for MRPL's crude cargo of about 707,500 barrels that arrived at India's Mangalore Port last week, Reuters quoted an informed source as saying.
Another source said MRPL might continue to get Iranian insurance cover for oil imports from Tehran.
"As long as we can avail of Iranian cover we will continue to import cargoes on that basis," the source said.
EU sanctions prohibiting European insurers and reinsurers from covering tankers carrying Iranian petrochemicals came into effect on May 1, forcing out most of the ships operating in the niche market.