In putting an end to one of Canada's first lesbian marriages, an Ontario judge has struck down sections of Canada's Divorce Act.

Justice Ruth Mesbur's ruling came in the case of a couple known in court documents as M.M. and J.H. They were among the first same-sex couples to tie the knot under Ontario's revised marriage laws.

They married on June 18, 2003, the week after the Ontario Court of Appeal legalized same-sex marriage in the province.

In June, they filed for divorce with Ontario Superior Court of Justice, shortly after signing an official separation agreement.

However, the Divorce Act states that only spouses, defined as a man and a woman, can get divorced. That put same-sex couples in the bizarre position of being able to get married but unable to legally split up.

Justice Ruth Mesbur ruled that was unfair.

"The definition of a spouse is unconstitutional, inoperative and of no force and effect," Mesbur said.

Lawyer Martha McCarthy, who represented one of the women, said the ruling is historic.

"We believe that this is not just the first gay or lesbian divorce in Canada, but actually the first gay or lesbian divorce in the world," McCarthy said.

When news of the case broke in July, Justice Minister Irwin Cotler agreed with lawyers for the couple that the Divorce Act as it stood was unconstitutional.

The federal government is awaiting an opinion from the Supreme Court of Canada on same-sex marriage, before going ahead with changes to laws.

However, courts in the provinces of Ontario, Quebec, and British Columbia have already legalized same-sex marriage.