NEW YORK (CNNMoney.com) - Stocks fell at the start Monday after oil prices approached $74 a barrel on fresh concerns that the West's standoff with Iran would result in crude supply disruptions.

The Dow Jones industrial average (down 12.41 to 11,247.87, Charts) fell about 0.4 percent and the broader Standard & Poor's 500 index (up 2.51 to 1,288.22, Charts) declined 0.3 percent after the market open.

The Nasdaq composite (down 0.45 to 2,219.41, Charts) lost about 0.4 percent.

Oil prices surged after Iran hinted it might use oil flows as a weapon in its nuclear dispute with the West and problems at U.S. refineries spurred worries over fuel supplies.

U.S. light crude oil for July delivery climbed 98 cents to $73.31 a barrel in electronic trading, after hitting a high of $73.45. The market had gained $1.99, or nearly 3 percent, on Friday

On Sunday, Iran's supreme leader, Ayatollah Ali Khameni, warned the United States that any "misbehavior" directed at Iran would serve to disrupt Gulf energy shipments.

Wall Street will also watch closely for any hints about what direction the Federal Reserve could take with interest rates in the months ahead when Fed Chairman Ben Bernanke delivers a panel address in Washington Monday at the International Monetary Conference.

In corporate news, a new study over the weekend showed Pfizer's (unchanged at $24.19, Research) anti-cancer drug, Sutent, shrank tumors and stopped them from spreading in the lungs and kidneys of patients.

The Wall Street Journal, reported over the weekend that the New York Mercantile Exchange (NYMEX) is in serious discussions with TSX Group Inc., owner of the Toronto Stock Exchange, about forming an alliance and possibly acquiring TSX's Natural Gas Exchange. Citing people close to Nymex, the paper said Nymex is considering offering TSX 10 percent of its equity for full control of Calgary's Natural Gas Exchange in a swap valued at roughly $150 million.

Nymex, the largest U.S. futures exchange for energy and metals, and TSX, the world's biggest market for energy and metals stocks, also aim to jointly offer commodities equities and futures through a single electronic-trading screen, the report said.

Treasury prices were unchanged, leaving the yield on the benchmark 10-year note at the 5 percent level hit late Friday. Treasury prices and yields move in opposite directions.

COMEX gold rose $5.50 to $646.50 an ounce.

In global trade, major Asian markets ended mixed Monday, hurt by weakness in Japan. Major markets in Europe were lower in early trading after last week's soft U.S. jobs report heightened concerns of an economic slowdown.

-----------------

Bill Gross: 'My bad' -- click here.

Click here for more breaking market news.