Shipping carriers have used general rate increases (GRIs) to raise Asia-US spot rates but many are sceptical that the rate increases will last due to low demand.

Carriers have already deferred the May 1 GRI to mid-May because cargo volumes have been unable to support the rate hikes, despite cancelled sailings planned in early May.

Despite double-digit gains, these are off a low base and there are no signs yet that trans-Pacific rate increases are supported by higher demand.

Analysts believe that the timing of the April 15 GRIs and the planned May GRIs coincide with the tail end of annual contract negotiations between ocean carriers and shippers.