The price of U.S. WTI crude futures, which lifted briefly above North Sea Brent crude Monday, dropped back Tuesday on short-term profit-taking.

During the previous session's London trading, West Texas Intermediate as traded on the New York Mercantile Exchange for both August and September delivery both traded above Brent crude's September price.

But with the expiration of the WTI August contract last night, the premium evaporated. WTI fell by $2 per barrel in the evening, and is trading around $1.50 below Brent.

At 0936 GMT, ICE Brent crude for September delivery was down 35 cents, or 0.3%, at $107.80 a barrel. Nymex crude for September delivery was down 65 cents, or 0.6%, at $106.30 a barrel.

"Profit-taking by short-term-oriented financial investors is doubtless to blame for the sharp fall in the price of WTI," Commerzbank said. "In recent weeks, they had played a major part in the 14% price rise observed since the beginning of the month."

The analysts noted that WTI was unable to sustain a move above $109 per barrel, which "is likely to have prompted initial investors to unwind their positions."

Economic data also played a role, according to Sucden Financial.

"The price decline was triggered by weaker-than-expected existing home sales in the U.S. , which fell 1.2% in June [on month] against the forecast of a 0.6% increase," wrote analyst Kash Kamal.

He also noted that there is an expectation of further draw downs in U.S. crude stocks this week, but that gasoline and other products stocks would need to simultaneously decline to keep crude prices high.

Petromatrix predicted a more volatile relationship between Brent crude and WTI in the near future.

"If the extra-ordinary backwardation in WTI cannot hold then we have to expect some rapid movements in the Brent-WTI [spread]," Petromatrix analysts wrote in a note to client. "The improvement in the U.S. crude oil infrastructure should result in more dynamic transatlantic crude oil futures markets."

Brent, meanwhile, seems to be on more of an even keel.

Oil production is likely to be suspended in South Sudan once again over disputes with neighboring Sudan . South Sudan is land-locked, so needs to maintain relations with its neighbor if it is to have an export route for its oil to the sea.

One of Libya 's main export terminals remains closed due to protests. These and other tensions in oil producing countries are likely to be supportive of the Brent price, since they could imply supply risk in the global oil market.

At 0937 GMT ICE gasoil for August was down $5.75, or 0.6%, at $912.75 a metric ton. Nymex gasoline for August was down 227 points, or 0.7%, at 3.0324 cents a gallon.

Διαβάστε ακόμα