(Adds analyst quotes and updates prices)
* Canadian dollar at C$1.3406, or 74.59 U.S. cents
* Loonie touches its weakest since March 15 at C$1.3455
* Bond prices turn lower across the yield curve
* 10-year yield touches a four-month low at 1.545 percent
By Fergal Smith
TORONTO, April 4 (Reuters) - The Canadian dollar weakened on Tuesday to a nearly three-week low against its U.S. counterpart, pressured by a loss of risk appetite and domestic data showing an unexpected trade deficit.
Following three consecutive months of surpluses, February's C$972 million deficit compared with economists' expectations for a surplus of C$500 million. It was the greatest fall in exports in nearly a year, fueled by a decrease in shipments of aircraft and canola. drop in exports will embolden the Bank of Canada to play down recent signs of strength in the domestic economy when it makes its interest rate decision next week, said Nick Exarhos, economist at CIBC Capital Markets.
"They are likely to continue to highlight that we are starting from a position of economic slack."
Risk aversion helped support the yen at the expense of commodity-linked currencies, such as the Canadian dollar, that tend to underperform when investors turn less optimistic about the economic outlook. for risk has been curtailed by market nerves ahead of a meeting between U.S. President Donald Trump and Chinese President Xi Jinping and following Monday's suspected suicide bombing in St. Petersburg, Russia.
The Canadian dollar CAD=D4 ended at C$1.3406 to the greenback, or 74.59 U.S. cents, weaker than Monday's close of C$1.3386, or 74.70 U.S. cents.
The currency's strongest level of the session was C$1.3374, while it touched its weakest since March 15 at C$1.3455.
Losses for the Canadian dollar came even as prices of oil, one of Canada's major exports, rose.
"On a day when oil is rallying you would expect the Canadian dollar to get a little bit of traction," said Win Thin, global head of emerging markets strategy at Brown Brothers Harriman.
U.S. crude CLc1 prices settled up 79 cents at $51.03 a barrel on expectations of a drawdown in U.S. crude and product inventories. some talk of some M&A flows that hurt the Canadian dollar yesterday and that carried over into today," Thin said.
Last week, ConocoPhillips (NYSE:COP) COP.N agreed to sell oil sands and western Canadian natural gas assets to Calgary-based Cenovus Energy Inc CVE.TO for C$17.7 billion.
Canadian government bond prices were lower across the yield curve, with the two-year CA2YT=RR down 2 Canadian cents to yield 0.738 percent and the 10-year CA10YT=RR falling 11 Canadian cents to yield 1.58 percent.
Still, the 10-year yield touched its lowest intraday since Nov. 30 at 1.545 percent.