TORONTO - The Canadian dollar was slightly lower against the American currency Tuesday amid a further decline in oil prices.

The loonie slipped 0.15 of a cent to 102.5 cents US.

The June crude contract on the New York Mercantile Exchange was down 20 cents at US$97.17 a barrel ahead of inventory data coming out later Tuesday. Crude has been heading lower for two weeks as investor grew concerned that slowing U.S. economic growth could undermine demand for crude.

Metal prices advanced as the July copper contract on the Nymex gained two cents to US$4.01 a pound while the June gold contract climbed $1 to US$1,491.60.

The Canadian currency has closed lower for the past four sessions, reflecting volatility in commodity markets as investors worry that the strong runup in prices for oil and metals has run its course for now.