AT TIME 0129LT POSITION 85NM WEST OF KARACHI WHILE DESCENDING THROUGH FL350 AIRCRAFT INITIATED MAYDAY CALL AND STARTED EMERGENCY DESCEND. THERE AFTER AIRCRAFT RESET SQUAWK TO 7700 EMERGENCY CODE. ON INQUIRY PILOT REPORTED CABIN PRESSURIZATION FAILURE AND REPORTED NO ASSISTANCE REQUIRED ON ARRIVAL. AIRCRAFT LANDED SAFELY AT TIME 0154LT. PERSONS ON BOARD 097.
