We just noticed last night how a few people who work for the BBC seem to also be parading around on C4 and I remembered my Dad saying something a while back about the BBC bailing C4 out financially or something.
Could be this, but it's nearly 2 years old
http://www.telegraph....e-with-Channel-4.html
Are you sure you're not just looking at programmes made by independant production companies (e.g. Endemol) who make progs for both broadcasters?
Chris Evans is currently working on a C4 programme, at the same time as he is contracted to BBC for the radio and The One Show. We thought of other current BBC people, just can't remember who they are now. They must just have good contracts.
There is no connection, though American viewers see Channel 4 programmes on cable channel "BBC America" which showcases the best of British TV, not just BBC programmes.
As Count-A-Strong says, Channel 4 programmes are often made at BBCTV Centre.
Channel 4 doesn't have any studios, all their programmes are made by indipendant production companies and those companies will use whatever studios suit them best.
A couple of years ago it was suggested that Channel 4 could merge with BBC Worldwide http://business.times...ia/article5321616.ece to prevent it going bust but I don't think anything came of that idea.
certainly bbc3 and bbc4 might as well be called itv 2 and itv 3, same old "reality" crap mostly. last night bbc3, some parents go abroad to spy on their teenage kids on a boys/girls holiday in malia. quality. not.