Melbourne: Exxon Mobil Corp. and BHP Billiton Ltd are studying plans to sell depleting energy assets in Australia, including the largest oilfield ever discovered in the nation.

The producers are considering marketing about 13 fields, licenses and associated infrastructure held in the Gippsland Basin Joint Venture, Exxon’s Esso Australia unit said Wednesday in a statement. Oil and gas production began from the venture in Australia’s Victoria-state in 1969, according to BHP.

“We are seeking to identify third parties with proven experience and strength to operate and capture the remaining potential in these licenses,” Esso Australia, which operates the venture, said in its statement. BHP and Esso Australia each hold a 50 per cent share of the joint venture.

Melbourne-based BHP’s Bass Strait unit, which includes the mining giant’s stake in the Gippsland Basin operation and a second joint venture, may be worth about $1 billion, Citigroup Inc. wrote in a May 27 note to clients. The unit’s liquids production is in decline, analysts including Sydney-based Clarke Wilkins wrote in the note.

Ageing assets

Asset buyers in the oil sector are favouring the purchase of individual operations rather than entire companies, allowing them to better target businesses and geographies that align with their strategy, Bloomberg Intelligence senior industry analyst Philipp Chladek wrote in a June 13 note. About 42 per cent of deals in the first half of 2016 were asset sales, compared with 5 per cent in the same period a year earlier, according to data compiled by Bloomberg.

Selling ageing energy assets fits with BHP’s strategy to divest “non-core, late life assets,” the producer said in a separate statement. BHP last year completed the demerger of a suite of smaller coal to manganese mining assets into Perth-based South32 Ltd.

Gippsland Basin fields to be marketed include Perch, Dolphin, Seahorse, Tarwhine, Kingfish A, Kingfish B, West Kingfish, Fortescue, Halibut, Cobia, Mackerel, Blackback and Flounder, Esso said in its statement. Kingfish, discovered in 1967, was the first offshore oilfield discovered in Australia and remains the largest, according to Exxon.