KARACHI, PAKISTAN, FEB. 15 -- Pan American World Airways resumed its operations in Pakistan today, five months after it suspended them in the wake of the bloody hijacking of a Pan Am airliner here.

Pan Am officials in Karachi said they would begin weekly flights to Bombay, despite their uncertainties over the Pakistani investigation of last September's hijacking of Flight 073. Pan Am flew the Karachi-to-Bombay route three times a week before the attack, in which the hijackers killed 21 people with grenades and rifle fire.