The Supreme Court today rejected a class action lawsuit alleging systematic discrimination against women in Wal-Mart's hiring and promotion practices, potentially reshaping standards for class action lawsuits.

Justices said there was not sufficient evidence of an explicit corporate policy against women, undercutting the women bringing the suit who charged that local managers had too much authority to make what they called arbitrary decisions about compensation and promotion. The suit was intended to cover every woman who had worked at Wal-Mart or Sam's Club since December 1998.

Justice Antonin Scalia wrote for the majority that proof of a discriminatory policy was entirely absent. The four other conservative justices joined Scalia's ruling while the four other liberal justices joined some aspects but dissented on others.

Wal-Mart is both the world's largest retailer and America's largest private employer.