(Bloomberg News) Bank of America Corp.'s Merrill Lynch unit must defend against a race-discrimination lawsuit on behalf of 700 black financial advisors, as the U.S. Supreme Court turned away a company appeal.

The justices today left intact a federal appeals court ruling that let the case go forward as a class action. The suing workers say that they are paid less than their white counterparts and that Merrill's policies are to blame. Bank of America, based in Charlotte, North Carolina, acquired Merrill in 2009, after the suit was filed.

The workers say black brokers were paid 33 percent to 42 percent less than white colleagues with the same job, education, experience and office location. The workers say the pay disparity stems from Merrill's policy of letting advisors work together on teams and its method of distributing the accounts of retiring or departing financial advisors.

The Chicago-based 7th U.S. Circuit Court of Appeals said the case could go forward as a class action to determine whether the two policies had a so-called disparate impact on black employees. Writing for the court, Judge Richard Posner said individual trials could be used to determine damages, if necessary.

Merrill argued unsuccessfully in its appeal that its case was similar to the Wal-Mart Stores Inc. class action blocked by the Supreme Court in a 2011 decision.

The brokers, led by George McReynolds, urged the high court to reject the appeal.