In an action by the US Department of Justice (DOJ) against aircraft engine-maker Rolls-Royce,[29]:4, 6, 9-12 the DOJ claimed that Rolls Royce had paid more than US$11 million in commissions to win a deal with Thai Airways, aware that some of the funds would be used to bribe officials at PTT and its subsidiary, PTT Exploration and Production (PTTEP). The payments were made from 2003-2013 and related to contracts for equipment and after-market products and services.[30] Admitting its guilt, Rolls-Royce paid US$170 million to settle the case.[31] PTT vowed to investigate.