SEEKING ALPHA -- May 20 -- The Telegraph said Saturday night that Yahoo is working to buy U.K.-based social network Bebo for $1-billion. Bebo has around 25m users worldwide, compared with MySpace's 100m or so registered users. Birch is rumoured to have turned down an offer from BT worth about £300m last summer. Viacom, the US media giant which was outbid for MySpace, is also believed to have made an offer last year. Bebo is backed by Benchmark Capital, the private equity firm.