LONDON (Bloomberg) — A glut of supertankers competing for two million-barrel cargoes of Middle East crude oil stayed unchanged, undermining owners' hopes of a rebound in rental rates as fourth-quarter trading begins.

There are 28 percent more very large crude carriers, or VLCCs, for hire over the next 30 days than there are cargoes, according to the median estimate of six shipbrokers surveyed by Bloomberg News today. That's the same as a week ago.

The oversupply is creating a "tangible" risk that shipping analysts will cut earnings estimates for VLCC owners in the fourth quarter and next year, Martin Korsvold and Wilhelm Gedde-Dahl, analysts at Pareto Securities AS in Oslo, said in an e-mailed note yesterday. Still, demand may accelerate this week before an oil-industry conference in Singapore and because booking levels are lagging prior months, they said.

Rental income from the industry's benchmark Saudi Arabia to Japan route has been below owners' daily running costs since Aug. 24, according to data from Drewry Shipping Consultants Ltd. and the Baltic Exchange, both based in London.

Crew, insurance and other running costs are $11,601 a day, Drewry estimates. Rental income has been below that for 29 sessions and slid 15 percent yesterday to $5,480 a day, according to the exchange.

The surplus in the Middle East averaged 21 percent in the third quarter, compared with a 9 percent excess in the three months to June 30.

Frontline Ltd., based in Hamilton, Bermuda, is the world's largest VLCC operator. Overseas Shipholding Group Inc. is the biggest US owner, while Euronav NV in Antwerp is the largest publicly traded carrier in Europe.

Frontline said on August 27 its VLCCs require $30,900 a day to break even. The figure includes financing costs.

Tanker operators lease the vessels on longer-term charters and in markets away from the Persian Gulf-to-Asia trade route where earnings can be higher than those achieved in the spot market.