SAN FRANCISCO — It’s been a big week for the Impact Fund and two gender discrimination class actions the Berkeley nonprofit has brought against discount retail giants. U.S. District Judge Edward Chen on Monday certified what lawyers say is the first class of women alleging gender discrimination since the U.S. Supreme Court’s blockbuster ruling in Wal-Mart v. Dukes.

In Ellis v. Costco, 04-3341, the plaintiffs allege, on behalf of a class of approximately 700 female class members, that Costco Wholesale Corp. consistently passes women over for promotions to assistant and general manager positions at retail locations. The suit brought by Jocelyn Larkin of the Impact Fund, the same shop behind Dukes, claims that Costco’s corporate policy of identifying and grooming prospective management candidates disparately impacts female workers, and that Costco executives were aware of the deficiencies but did nothing to rectify them because of orders from Costco’s chief executive officer.