I have a co-worker who is a compulsive talker. He constantly interrupts others and hijacks the conversation, proceeding to talk endlessly if not interrupted in turn. If left to talk by himself, he will often ramble and even interrupt himself to start a new topic. I suspect that the roots may be stress, anxiety, or potentially some other undiagnosed condition.
He is very competent and makes very valuable contributions to our projects, to the point I would regard him irreplaceable in our team. However, during presentations and meetings his behaviour is a problem, since he never lets others finish their sentences and causes trivial meetings to turn into a fight for the right to talk.
He is aware that he talks too much and apparently has been told so before by other people. Sometimes when called out, he politely allows others to speak, but it doesn't always work. Moreover people who aren't aware of this characteristic of his simply don't dare to call him out.
Since he is an essential part of our team, it is evident that he needs to partake in meetings, but how should we do so that we manage to discuss everything and everyone manages to get their points through?