Boeing's 787 Dreamliner: It wasn't batteries that caused fire say officials

British officials say links to any battery-related problems have been ruled out

British officials said initial checks into a fire on board a Boeing 787 Dreamliner appeared to rule out any link to the battery-related problems that grounded the Dreamliner fleet three months earlier this year.

Airlines expressed confidence in the safety of the aircraft on Sunday as investigators searched for the cause of a fire on one of the advanced jets and billions were wiped off the company's market value.

Britain's AAIB said on Saturday there was extensive heat damage in the upper portion of the rear fuselage. The damage was far from the batteries and “there is no direct evidence of a direct causal relationship”, it stressed.

The fire on the Ethiopian Airlines plane at Heathrow Airport in London, followed by a separate technical problem on a second 787 owned by Britain's Thomson Airways on Friday raised new questions about the safety of the aircraft.

The incidents were a setback for a company attempting to rebuild the public's confidence in its flagship jet and compete with Airbus in the booming market for more fuel-efficient long-distance planes.

Britain's Tui Travel, which owns six European airlines including Thomson Airways, said its plane turned back during a flight from England to Florida and had a small number of unspecified components replaced. The parts were unrelated to the battery, it added.

A TUI Travel spokeswoman said: “We want to reassure our customers that we have every confidence in this aircraft and would never operate it if we weren't 100 percent sure of its safety.”

No passengers or staff were injured in the fire on the empty Ethiopian Airlines plane, which occurred when the vessel was parked at Heathrow. However, it closed Britain's busiest airport for 90 minutes.

Boeing shares closed down 4.7 per cent at $101.87 on Friday after the Heathrow fire, knocking $3.8 billion off the company's market capitalisation.

In the early stages of the investigation, airlines said they would continue to fly their Dreamliners, while others confirmed they would still purchase the aircraft.

Virgin Atlantic said it remained committed to taking delivery of 16 of the planes from the autumn of 2014. Delta Air Lines is buying a 49 per cent stake in the airline.

“We are confident that Boeing and the relevant authorities are working hard to ensure that the appropriate action is being taken,” Virgin said in a statement.

Polish flag carrier LOT, the first European airline to take delivery of the 787 last year, said it was in constant contact with Boeing.