Abraaj Group, the Middle East buyout firm roiled by allegations of misused funds, is considering the sale of a stake in its fund management business to raise cash amid heightened regulatory scrutiny and the departure of key executives, according to people with knowledge of the matter. The group has held discussions with advisers about selling part of the newly separated investment business, which oversees funds globally for institutional investors, the people said, asking not to be identified as the matter is private.