* TSX down 45.47 points at 12,101.79
* U.S. jobless claims rise; home sales trend higher
* Eight of index's 10 sectors lower (Updates to close)
By Claire Sibonney
TORONTO, Sept 23 (Reuters) - Toronto's main stock index fell for the third straight session on Thursday, as bearish U.S. economic data prompted many wary investors to lock in profits made in an unusually strong September.
After teetering around the unchanged mark for much of the day, the hefty energy and materials groups, each down 0.5 percent, dragged the TSX lower, despite rises in oil, copper and gold prices. [O/R] [MET/L] [GOL/]
Barrick Gold ABX.TO reversed its earlier gains to fall 0.9 percent to C$48.23, while oil company Canadian Natural Resources CNQ.TO fell 1.1 percent to C$33.11. Base-metals miner Teck Resources TCKb.TO dropped 2 percent to C$39.10.
The TSX index's decline followed fresh signs of U.S. labor market weakness, which rekindled fears that the U.S. economic recovery remains anemic. [.N] [MKTS/GLOB]]
"Concerns are once again coming about the pace of recovery in the U.S.," said Elvis Picardo, analyst and strategist at Global Securities, in Vancouver.
Data on Wednesday showed U.S. weekly claims for jobless insurance jumped unexpectedly. Another report showed existing home sales rose in August, though the gain was from severely depressed levels. [ID:nN23130114]
Picardo also pointed to a slide in Canadian retail sales in July, reported on Wednesday, and a U.S. Federal Reserve statement on Tuesday that hinted it may embark on a new round of monetary stimulus, which unsettled some investors who had become more optimistic about the economy's prospects.
"We've noticed that in the days immediately following the Fed's meeting, you normally see sustained weakness in the markets for a period of time."
Economically-sensitive financials, which had rallied earlier in the day, lost 0.2 percent as Royal Bank of Canada RY.TO slipped 0.1 percent to C$52.60 and Bank of Montreal BMO.TO fell 0.8 percent to C$58.84.
"What this market really needs to get a sustainable long-lasting rally is a little more conviction in the economic data coming out that shows that in fact the recovery is improving better than what the Street is expecting it to," said Gareth Watson, Canadian equity advisor at ScotiaMcLeod.
He was referring to both crucial employment and real estate prices in the United States.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed down 45.47 points, or 0.37 percent, at 12,101.79. Eight of the index's 10 main sectors were weaker. The cyclical industrials sector, off 0.9 percent, was the hardest hit, pulled lower by Canadian National Railway CNR.TO, down 1.7 percent at C$64.99.
Still the index is up almost 6 percent since late August and on Monday it had rallied to its highest closing level since April.
"The fact that we've had such an unusually strong September ... that's possibly causing some investors to take some money off the table before the end of the month and end of the quarter," added Picardo.
"Given that October is traditionally a rocky month for equity markets, I think it's quite likely that some investors are jumping the gun and getting out while the going is good."
Also weighing, Potash Corp POT.TO fell 0.5 percent to C$150.50 after filing a lawsuit against BHP Billiton BHP.AX BLT.L to fend off the miner's $39 billion hostile takeover bid, intensifying the Canadian fertilizer supplier's struggle to find a more attractive offer. [ID:nN22227579]
On the bright side were telecoms, up 0.3 percent, and the healthcare sector, up 0.4 percent. Biovail BVF.TO, Canada's biggest publicly traded drugmaker, jumped more than 4 percent to C$27.70 ahead of next week's shareholder vote on its merger with Valeant Pharmaceuticals International.
($1=$1.03 Canadian) (Additional reporting by Jennifer Kwan; editing by Jeffrey Hodgson)