The loonie edged 0.19 of a U.S. cent lower to 79.52 cents.
The April crude contract in New York was lower for a fourth consecutive session after data last week showed American oil supplies at 80-year highs.
On Monday, crude dropped $1.36 to US$49.45 a barrel. Prices have fallen about 40 per cent since the end of November amid a huge oversupply of crude on world markets.
Metals were mixed with March copper unchanged at US$2.59 a pound while April gold faded $4.10 to US$1,200.80 an ounce.
The U.S. Federal Reserve is also in focus this week with chairwoman Janet Yellen set to deliver her semi-annual testimony on the economy and monetary policy to Congress on Tuesday and Wednesday.
Traders will look to her remarks for indications on when the Fed might start raising interest rates. Many analysts think the Fed could move as early as June.
Meanwhile, the Greek government will submit proposals to debt inspectors on Tuesday as its seeks to receive final approval for the latest instalment of bailout money from its eurozone creditors.
The Greek government and its creditors agreed Friday to extend the country's rescue loans by four months. In return, Greece must commit to a string of budget measures meant to keep a lid on debts and improve the economy.