TWO BITTER rivals jostling to supply Timor Sea gas to northern Australia and beyond have decided to set aside their differences for a co-operative development costing up to $6.8 billion. According to industry sources, Phillips Petroleum and Woodside Petroleum have reached a preliminary agreement on amalgamating their respective Bayu/Undan and Sunrise Gas projects, which lie some 200 kilometres apart and 500 kilometres from the Northern Territory's capital of Darwin.