The recent decision by Petronas, the Malaysian state energy group, to take a stake in Rosneft, the Russian oil producer, underscores worries about Malaysia's dwindling oil reserves.

The $1.1bn deal to gain access to Russia's oil fields comes as Petronas recently reported that domestic oil production last year fell by nearly 5 per cent to 700,000 barrels a day. Malaysia's is south-east Asia's largest oil producer after Indonesia.