Shares in Spire Healthcare Group Plc (LSE:SPI) jumped more than 6% this morning after Sky News reported that buyout firm Bridgepoint is drawing up plans for a formal offer worth around 230p a share, valuing Britain's biggest private hospitals operator at more than £1 billion. According to Sky News, Bridgepoint, the former owner of Oasis Healthcare, the dentistry chain previously run by Spire's own chief executive Justin Ash, is serious about a bid, though a formal offer may not arrive before a Takeover Panel "put up or shut up" deadline of 5pm today.