FILE PHOTO: The logo of Indonesian state energy firm Pertamina is seen in Jakarta January 26, 2011. REUTERS/Supri JAKARTA : Pertamina International Shipping, a unit of Indonesia's state energy firm, aims to invest up to $3 billion over the next five years to rejuvenate and expand its fleet, including investing in vessels to transport liquefied natural gas, an executive said. Pertamina International Shipping (PIS) operates more than 400 vessels, including three very large crude carriers (VLCC) and two very large gas carriers (VLGC).