* Energy, financials lead TSX retreat
* Materials only advancer as gold issues shine
* Suncor biggest decliner, reports rare loss (Adds details, official numbers, analyst comments)
By Natalie Armstrong
TORONTO, Jan 20 (Reuters) - Toronto's main stock index fell 3.8 percent on Tuesday as a relentlessly gloomy global economic outlook spurred a broad-based selloff led by energy and financial issues.
While oil prices jumped 6 percent ahead of the expiration of the February U.S. futures contract, energy shares led the TSX retreat, slumping 6.8 percent.
Shares of Suncor Energy (SU.TO), the day's biggest decliner, slumped 15.84 percent to end at C$22.10 after Canada's second-biggest oil sands producer reported its first quarterly net loss in 16 years. It also announced it was slashing capital spending and halting a C$20.6 billion oil sands expansion. [ID:nBNG347039]
EnCana (ECA.TO) shares ended 5.5 percent lower, at C$52.67.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed down 336.55 points, or 3.81 percent, at 8,504.93. All but one of its 10 main sectors ended lower.
The TSX opened slightly higher after the Bank of Canada cut its overnight rate by 50 basis points to 1 percent [ID:nN20403457]. But the market quickly turned negative and stayed there all day.
Financial issues sank 5.8 percent over lack of confidence in the global banking sector after Royal Bank of Scotland (RBS.L) announced the biggest loss in British corporate history on Monday.
"All of our banks are down big time, basically the same situation as in the U.S., basically the same situation in the U.K.," said Fred Ketchen, director of equity trading at ScotiaMcLeod.
"That whole financial services sector is weeping badly and it looks as though it's going to continue a little while longer."
The materials group was the lone advancing sector on the TSX, ending up 1.4 percent, buoyed by the gold sub-sector which gained 3.3 percent as gold prices climbed more than 2 percent on safe-haven buying over bank worries.
$1=$1.27 Canadian Reporting by Natalie Armstrong; editing by Rob Wilson