The reductions were two cents a litre for diesel and four cents for petrol, except for so-called ultra-premium petrols, which fell by three cents.

The latest adjustment brings a litre of 92-octane petrol to $2.133 a litre before discount; 95-octane to $2.166; and 98-octane to $2.24.

Shell's V-Power is now $2.369, while Caltex's Platinum is $2.366.

Diesel returned to sub-$2 level to $1.993.

The slide follows a sustained drop in international crude oil prices. Light, sweet crude for August delivery ended last week at US$128.88 a barrel on the New York Mercantile Exchange.

A week earlier, it hit a record US$147.27.