Lockheed Martin Corp, the largest US arms maker and parent of Sikorsky, has begun to study the possibility of selling commercial helicopters to Iran, but said the market may be small and the company still needed guidance from the US government.

Lockheed, along with Boeing Co, is one of the first major US aerospace companies looking into selling to Iran for the first time since US sanctions were imposed following Iran's Islamic Revolution of 1979.

European aircraft manufacturers already are starting to get orders from Iran after sanctions were lifted on January 16.

Nathalie Previte, vice-president of sales and marketing for Sikorsky, said the company had received numerous inquiries from existing customers, including leasing companies and operators, interested in possible helicopter operations in Iran.

Sikorsky's S-76 and longer-range S-92 commercial helicopters could be options for Iran, Previte said, although she added that the country has little of the offshore drilling activity that drives helicopter demand in the oil and gas sector.

"I want to understand the US government's policy about what can be done and what can we not do, and really clear everything with the US government even before we start completing the analysis," Previte told Reuters at the Berlin Air Show.

Previte's comments marked the first time Lockheed has acknowledged looking into possible sales to Iran. The company is mainly a government and defence contractor, but entered into the commercial market with its purchase of helicopter maker Sikorsky from United Technologies Corp last year.

Sikorsky is studying which of its products could be sold in Iran but is still working through the regulatory and compliance issues with the US government, Previte said. She added it was unclear how big the market could be.

Boeing Co Chief Executive Dennis Muilenburg on Thursday said Iran's demand for airliners was real, and the prospect of a major order there was moving closer.

Airbus in January agreed to sell Iran 118 planes worth about $27 billion at list prices, and says it also sees Iranian demand for helicopters.

AgustaWestland, a unit of Italy's Leonardo Finmeccanica, also has seen interest in its helicopters from operators looking to do business in Iran, industry sources said. - Reuters