India's aviation safety watchdog said on Tuesday surveillance conducted on Air India's Boeing 787 fleet did not reveal any major safety concerns, days after one of its jets crashed, killing at least 271 people.

Investigators have recovered the cockpit voice recorder (CVR) from the crashed Air India flight, a key step in uncovering what caused last week's deadly accident.

Stricter environmental regulations and slower global economic growth will soften marine fuel demand in the coming years, the International Energy Agency said in its annual report on Tuesday.