Brunei–Malaysia border which are defined by agreements, from west to east, are as follows: Brunei and Malaysia in an Exchange of Letters on 16 March 2009, agreed to affirm the five agreements. The two countries also agreed to use the watershed principle to determine the remaining undelimited portions of the border. Brunei's maritime boundary with Malaysia until the 100 fathom isobath was inherited from the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 and the North Borneo (Definition of Boundaries) Order in Council 1958 No 1517, both of which defined the boundary between Brunei on the one hand, and Sarawak
Brunei–Malaysia border of Boundaries) Order in Council 1958. In 1979, Malaysia published a territorial waters and continental shelf map showing the area claimed by Brunei as its continental shelf/EEZ as belonging to Malaysia. The map also depicts the Brunei-Malaysian border as only running up to the 100 fathom isobath. Brunei does not recognise the assertions made by Malaysia. In 2000, Brunei had earlier awarded a concession for a petroleum block called Block J to Shell, Mitsubishi and ConocoPhillips and Block K to France's Total, BHP Billiton and Hess Corp. Subsequently, in 2003, Malaysia's national petroleum company Petronas awarded concessions to its subsidiary