Khalid Alsweilem, a former senior official at Saudi Arabia's central bank says he believes the kingdom may soon change the way it manages its oil wealth as part of efforts to protect its financial reserves in an era of cheap crude. The Saudi Arabian Monetary Agency ( SAMA ) manages the vast bulk of petrodollars earned by the world's top oil exporting country; net foreign assets at the central bank totalled $664.5 billion in June. Alsweilem, who managed the assets as chief investment officer at SAMA , argues the arrangement is dangerous because the finance ministry can draw freely on the reserves when it wants to cover budget deficits caused by periods of low oil prices.