Advertising: The acquisition and turnaround group Redbus yesterday bought Streetbroadcast, the largest lamp-post advertiser in Britain, two months after the company went into administration. Streetbroadcast was owned by a consortium of heavy-hitting investors including Apax Partners, New Smith Capital Partners and Vincent Tchenguiz’s Consensus Group. Yet it was put into administration at the start of March after the backers decided against further investment in the group, which has struggled since the onset of the credit crunch.