IRVINE, Calif.—William Ackman's Pershing Square Capital Management proposed on Monday a slate of six directors for the board of Allergan Inc. as the hedge fund moves forward with its takeover bid with Valeant Pharmaceuticals International Inc., according to a report from Reuters.

Pershing Square nominated Betsy Atkins, chief executive officer of venture capital firm Baja; Cathleen Black, senior adviser at RRE Ventures who was also a former chancellor of New York City's public schools and a former president of Hearst Magazines; Fredric Eshelman of investment firm Eshelman Ventures; Steven Shulman, managing director of Shulman Ventures, a private equity firm; David Wilson, former CEO of the Graduate Management Admission Council, and John Zillmer, former executive chairman of chemicals distributor Univar Inc.

Pershing Square is pushing for a special meeting of Allergan shareholders to consider the removal of six incumbent directors and the appointment of its slate of nominees. Canada's Valeant has said it already has enough shareholders on its side to call the meeting. It would need the support of holders of at least 25 percent of the shares.

Allergan is expected to unveil details of its plan to remain a standalone company when it releases second-quarter results sometime in July. The company has said it is considering acquisitions of its own, additional spending cuts or taking on debt to buy back shares.