ExxonMobil Marine Fuels (EMMF), the world's largest supplier of marine fuels, is increasing its involvement in the bunker production and supply market serving the United States Gulf region. Initially, production expansion is being centred on EMMF's facility at Beaumont, Texas, which has a fuel run of approximately 400,000 barrels a day. The company is also working with its refinery and supply groups to optimize fuel oil production at other ExxonMobil refineries.