The Supreme Court of Canada has unanimously upheld a lower court ruling that ordered a wealthy Toronto man to pay $10,000 a month in child support.

The case involves Thomas Baker, who earns close to $1 million a year and in 1997 was estimated to have a net worth of about $78 million.

His ex-wife, Monica Francis, earns about $60,000 a year as a school teacher. Francis has custody of their two daughters, who live with her in a four-bedroom home in a "modest" Toronto neighbourhood.

The lower court had ruled that Baker should pay his ex-wife more than the $2,500 they had agreed to in their initial separation agreement.

Baker was ordered to pay $10,000 a month to Francis in child support -- plus a $500,000 lump sum to ease her financial problems.

Baker had argued the support amount was excessive. He said he shouldn't have to pay just because he made more money than his wife.

Baker's lawyer argued to the Supreme Court that his client was adequately providing for his children and that the lump sum would be an unfair windfall for his ex-wife.

Francis' lawyer argued that this case was about trying to equalize the standard of living between the two households.

The Supreme Court ruled in favour of Francis, arguing that they had no evidence that the amount Baker had been ordered to pay was unfair or inappropriate.

Francis and Baker married in 1979 and lived together for several years before separating shortly after their second daughter was born.

Baker made his fortune after the couple were divorced.