Call it an April Fool's joke, but beginning April 1, 2013, Qantas is cutting the luggage weight allowance of its business class passengers to a maximum of 52 kilogrammes from 96.

The change is part of the Australian flag carrier's alliance with Middle Eastern carrier Emirates which used weight alone in determining luggage allowance of its air passengers.

Qantas used the weight-only system for a long time but shifted to the piece and weight system in May 2012. However, the shift favours economy ticket holders, but not business class passengers who used to enjoy a baggage weight allowance of 96 kg split into three bags of 32 kg each.

However, Qantas Club or Silver members flying on a premium-economy seat on an international flight are allowed three pieces of bag of up to 23 kg each, but their total allowance is only 52 kg. Those with economy tickets would have a 30 kg allowance, up from 23 kg.

The new policy, which includes travelers from America, who used to enjoy higher luggage weight allowances, affects all passengers who booked flights on or after Feb 26 and are flying Mar 31 or later. Qantas explained the move aims for a more seamless experience for travelers on the joint network.

"As part of the alignment Emirates will increase its pre-purchase excess baggage discount to 30 per cent," Qantas said in a statement.

On the plus side, Emirates will introduce a new Platinum level to its Skywards frequent flyer programme which would mean their top tier members would enjoy benefits extended to Qantas Frequent Flyer Platinum members.

Emirates business travelers who reach 150,000 tier miles would be eligible for the platinum level in the Skywards programme, while the benchmark would be 50,000 tier miles for Gold members and 25,000 for Silver members.

With the changes, about 5 per cent of current Emirates Gold members who number about 110,000 would qualify for Platinum membership and benefits such as access to first class lounge in Dubai, 75 per cent extra bonus Skywards miles and 20 kg extra luggage allowance regardless of cabin type.