Commodity currencies slumped early on Monday while the safe-haven yen soared after global oil producers failed to agree on an output freeze, sending oil prices tumbling anew.

The Canadian dollar and its Australian counterpart were both marked more than 1 percent lower to as low as C$1.2957 per USD and $0.7594 in early trade.

The loonie last stood at C$1.2952 per USD, while the Aussie was at $0.7663, both down about 1 percent.

A deal to freeze oil production by OPEC and non-OPEC producers fell apart on Sunday after Saudi Arabia demanded that Iran join in despite calls on Riyadh to save the agreement and help prop up crude prices.

"There was some speculation ahead of this weekend's summit that an agreement to freeze crude oil production could be reached," analysts at Commonwealth Bank said.

The failure to secure a deal unsettled markets. U.S. crude futures slid 6.7 percent to $37.68 a barrel, while Brent futures dropped 6.7 percent to $40.18 a barrel.

Investors rushed to the safe-haven yen, sending it to three-year highs against the euro. The common currency briefly dipped below 122.00 yen for the first time since April 2013, but has since drifted back to 122.25 yen.

The dollar came within a whisker of an 18-month trough of 107.63 yen set recently, before steadying at 108.27.