NEW DELHI -A preliminary investigation into the crash of an Air India passenger jet last month that killed 260 people raises additional questions about the incident and the investigation is far from over, Air India's CEO said in a memo on Monday.

CEO Campbell Wilson said in an internal memo that the airline is open to further inquiries and warned against "premature conclusions."

He said the airline will continue to co-operate with the investigators to ensure they have everything they need to conduct a thorough and comprehensive enquiry.