Hedge funds and other money managers raised their combined net long position in the six most important petroleum contracts by just 3 million barrels to 1.049 billion barrels.

Fund managers boosted their net position in Brent (+28 million barrels) and US gasoline (+4 million) but cut positions in US heating oil (-4 million), European gasoil (-9 million) and WTI (-16 million barrels).

Diverging attitudes towards Brent and WTI have become the most notable short-term trend among hedge funds Portfolio managers have boosted their net position in Brent by 143 million barrels in the last four weeks, an increase of 44 percent, including by 51 million barrels in the two most recent weeks.

At the same time, fund managers have trimmed their net position in NYMEX and ICE WTI by 44 million barrels in the last fortnight.

Hedge funds hold nearly 16 bullish long positions in Brent for every bearish short one, up from a ratio of 6:1 at the end of May, and far ahead of the ratio of 9:1 in WTI.

Fund managers are betting the introduction of sanctions on Iran will result in a shortage of seaborne crude on international markets even while the landlocked US inland market remains plentifully supplied.