By Jess Jones Abu-Dhabi backed fund Redbird IMI has formally launched the sale of The Telegraph and The Spectator as bankers have tracked down one of the media group’s owners to serve him with a bankruptcy petition. Redbird IMI has sent a sales document to potential buyers, with first-round bids expected by late July and a deal anticipated later in summer, according to the Financial Times. The sales process has attracted more than 20 potential buyers, including investment groups and media owners from the UK and abroad. Prospective buyers can bid for either The Telegraph or The Spectator, or bo…