PARIS—French President Nicolas Sarkozy urged his political allies to treat International Monetary Fund Managing Director Dominique Strauss-Kahn with dignity one day after he was ordered held without bail on sexual-assault charges, while France's broadcasting watchdog called on television networks to show restraint in their coverage of him.

Mr. Sarkozy urged members of his conservative ruling party not to appear to be taking advantage of the legal woes of the Socialist Party stalwart, who was arrested by New York police on...