Blackstone Group has given up its bid for Dell, less than a month after the private-equity fund manager said it was planning to top an offer from founder Michael Dell and private-equity firm Silver Lake Partners, according to news reports. In the so-called "go-shop" period for alternative bidders to make their offers, Dell received two counter-offers related to its plans to go private, with bids coming in from Blackstone and entities associated with investor Carl Icahn. It is not clear whether Icahn's bid still continues.