One of her advisers, Hrannar B. Arnarsson, said Monday Prime Minister Johanna Sigurdardottir and writer Jonina Leosdottir were officially married Sunday, the day the law came into force.

The pair has been in a registered partnership since 2002 and had applied to have it converted into a marriage under the new law. No ceremony was held.

The law was passed without a dissenting vote in Iceland's parliament June 11.

Social Democrat Sigurdardottir, 68, became Iceland's prime minister last year, after the previous center-right government was ousted by a wave of protest triggered by the country's economic crisis.