TORONTO (Reuters) - Toronto's main stock index finished lower yesterday, ending a string of four straight higher closes, hit by a plunge in mining giant Barrick Gold Corp and concerns about the economy.

Barrick, the world's No 1 gold miner, was the largest drag on the index as investors reacted to the dilutive impact of a planned equity offering that it said could be worth as much as $4 billion.

The news combined with a slide in gold prices to send the materials sector down 2.25 percent, the biggest drop among all of the TSX's 10 sectors.

"The offering price was lower than (Barrick's) market close yesterday and that dragged down the index," said John Ing, president of Maison Placements Canada. "That together with gold touching $1000 and then pulling back ... hurt the other stocks at the same time."

Shares of Barrick Gold ended down 6.5 percent at C$39.71, while Goldcorp shares slipped 3.8 percent to C$42.61.

The financials index, which makes up about 30 percent of the broader index, fell 1.7 percent. Key drags in the sector were Royal Bank of Canada, which fell 1.6 percent to C$55.91, and Bank of Nova Scotia, which slipped 2 percent to C$43.87.

The S&P/TSX composite index ended down 105.13 points, or 0.95 percent, at 11,000.17, one day after it shot to its highest level since October 3, 2008.

The lower close came a day before the Bank of Canada makes a scheduled announcement on key interest rates in a statement that is expected to offer the central bank's view of the state of the domestic economy.

The TSX is now up 47 percent from the five-year low it hit in March, leaving some investors eager to pocket some of those gains in the first days back after summer holidays.

"It's a lot to do with valuations as well. The Bank of Canada makes its monetary policy announcement tomorrow so there might be some concern as to what they are going to say about the state of the economy," said Elvis Picardo, analyst and strategist at Global Securities in Vancouver.

"The assumption behind the entire move in the markets has been that the economy is rebounding faster than expected, so any cautionary comments from the Bank of Canada could weigh on the market."

The pullback in the TSX also came as domestic data showed housing starts rose 12.1 percent in August from July, more than forecast, largely from big gains in construction of condos and apartments.