San Francisco: US aerospace giant Boeing has signed a contract valued at $7 billion to supply 12 of its 787 Dreamliner aircraft to Gulf Air, with options for six additional jets. The agreement, announced Thursday, comes as the Bahrain-based airline seeks to expand its global reach and modernise its fleet.

The sudden movement of engine fuel switches has taken centre stage in the investigation of the Air India Boeing Dreamliner crash that killed 260 people in June, the world's worst aviation disaster in a decade.

A preliminary report released last week included detail about the fuel, saying that the fuel to the plane's engines appeared to have been shut off.