Prime Minister David Cameron is renegotiating his country's membership of the 28-member trading bloc and could reach a deal with EU partners at a summit next month, paving the way for a public vote as soon as June.

Chief Executive Ben van Beurden told the Sunday Times newspaper that the Anglo-Dutch firm, which is currently seeking shareholder approval for its bid to acquire Britain's BG Group, could suffer were Britain to leave the bloc.

"We are a company with a strong heritage in the UK and on the Continent. There would be a real break between the two, which would affect freedom of movement of staff, trade — we would be impacted," he was quoted as saying by the newspaper.

"There will be a path of divergence, and that will have all sorts of inefficiencies. That’s not good for companies like ours that thrive by there being no barriers. That is a fundamental economic aspect of it."

Several large British businesses have spoken out in favour of the EU, often due to tariff-less trade which they benefit from, although many smaller firms have criticised the bloc for imposing what they argue are costly regulations.

Van Beurden also said the firm's $48 billion bid for BG Group, which has faced shareholder criticism as the oil price drops to a 12-year low, made sense and that he hoped that it would be approved by more than a "narrow margin."

"This deal makes sense if over the next 20-30 years the oil price is above the low $60s. At that level it is value accretive. I think that’s an entirely reasonable, sensible risk to take," he said.

(Reporting By Costas Pitas; Editing by Elaine Hardcastle)