At the same time, the prospect of a supply glut from more corporate bond sales hangs over the market.

The supply glut was aggravated in the last two years by the severe economic problems in Asia, Russia and Latin America.

The investigation comes at an awkward time for L.C.D. makers; prices plummeted in the first half of 2006 because of supply gluts.

The reasons for the long decline in oil prices include a supply glut, brought on largely by new finds outside the Middle East.

Such Treasury auctions by themselves can cause prices to drop by raising the prospect of a supply glut.

The fall in demand causes a fall in prices as a supply glut develops.

Analysts attributed the run-up in recent days to heavy winter demand, a new system for gauging inventories, and fear of a supply glut from Iraq.

But there have been recent signs that this supply glut is beginning to turn.

Today's Columns Stocks of aluminum companies have risen as the industry has sought to correct a worldwide supply glut.

But what the Saudis want to avoid is increasing production capacity so much that they unwittingly create a new supply glut.