The insurance outfit IAG has been judged the worst transnational company operating in New Zealand.

It's taken out the annual Roger Award, which is organised by unions and anti-foreign ownership campaigners.

Judge Deborah Russell said IAG has behaved in a callous way towards people in Christchurch, by refusing to pay out insurance and engaging in shoddy repairs.

Another judge, activist Sue Bradford, said the degree of suffering IAG has been responsible for in the city seems phenomenal and abhorrent.

Serco came second in this year's Rogers, and Bunnings is third.