The Toronto Stock Exchange plummeted lower on Wednesday for its fourth consecutive drop, bringing benchmark index’s total loss so far this week to nearly 600 points.

The S&P/TSX composite index dropped 241.29 points, or 2.3%, to close at 10,066.11. Since Friday’s close, the benchmark index has shed 578.85 points.

Energy shares tumbled 3.5% on Wednesday despite a small boost in crude prices. Crude oil for July delivery finished up 56¢, or 0.8%, at US$71.03 a barrel on the New York Mercantile Exchange.

Shares of Suncor Energy Inc. tumbled $1.88, or 5.2%, to $34.30 and Husky Energy Inc. plummeted 5.7% to $31.35.

Nexen Inc. fell 4.3% to $24.68 and Petro-Canada finished at $43.33, down 5.2%.

TransCanada Corp. shares dropped 5.1% after the company announced on Tuesday that it would buy the remaining stake in the Keystone pipeline from U.S. energy giant ConocoPhillips for US$550 million. TransCanada shares shed $1.69 to $31.37.

Meanwhile, gold for August delivery rose US$3.80, or 0.4%, to end at US$936 an ounce on the Comex division of the New York Mercantile Exchange.

But the boost failed to resonate among materials stocks in Toronto, which fell 3.4%. The sub-gold index slipped 0.3%.

Goldcorp Inc. fell 1.3% to $38.67 and Yamana Gold finished at $10.37, down 1.1%.

Shares of First Quantum Minerals Ltd. tumbled $2.70, or 5.1%, to $50.51.

Shares in PotashCorp. tumbled more than 10% after it said it would cut 2009 production by 800,000 tonnes. Potash shares fell $12.66 to $108.34.

Agrium Inc. saw its shares fall a sharp $3.76, or 7.2%, to $48.49.

The financials group finished the day down 1.7%.

Manulife Financial Corp. dropped 3.8% to $22.51 and Sun Life Financial Corp. fell 3.8% to $30.09.

CIBC shares shed 1.9% to $53.02.

Also lower was Royal Bank of Canada, down 1.4% to $44.03.

Consumer staples stocks comprised the only main group on the TSX to advance on Wednesday, edging up 0.1%.

Shares of convenience store operator Alimentation Couche-Tard Inc. added 51 cents, or 4%, to $13.23.

The S&P/TSX Venture index fell 23.82 points, or 2.1%, to end at 1,115.37.

The Canadian dollar advanced a third of a cent to close at US88.42¢.

In New York, the main U.S. stock market indexes finished the session mostly flat, unchanged by the U.S. government’s proposals for reform of financial sector regulation.

The Dow Jones industrial average finished at 8,497.18, down 7.49 points, or 0.1%.

The S&P 500 index dipped 1.26 points, or 0.1%, to close at 910.71.

The Nasdaq composite index rose 10.88 points, or 0.7%, to end at 1,808.06.

IE