The Globe and Mail reports in its Thursday edition that Indigo Books & Music has seen an exodus of nearly half of its board of directors and has announced founder Heather Reisman will retire later this summer. The Globe's Susan Krashinsky and David Milstead write that Indigo said Wednesday that four of its 10 directors have stepped down: Frank Clegg, Howard Grosfield, Anne Marie O'Donovan and Dr. Chika Stacy Oriuwa. Indigo also wrote in a release that Dr. Oriuwa resigned "because of her loss of confidence in board leadership and because of mistreatment." Before her resignation, she had served on Indigo's human resources, compensation and governance committee. Ms. Reisman has served as chairman since last September, when she stepped back as chief executive officer, promoting Peter Ruis to the top job. On Wednesday, Indigo announced Ms. Reisman plans to retire from the board on Aug. 22. All four of those who have departed were independent directors, leaving the Indigo board with three independent and three non-independent directors -- the latter including Mr. Ruis; Ms. Reisman's daughter, Andrea Johnson; and Ms. Reisman's husband, Onex chairman Gerald Schwartz, who is also Indigo's controlling shareholder.