Is it possible to buy stocks online with bitcoin.. the stocks listed on NYSE, NASDAQ and London Stock Exchange among others ?
Not that I'm aware of, in terms of dealing with traditional publicly-facing companies on the exchanges you mention. There were a number of attempts to create new, bitcoin-only exchanges for privately held companies, but few have gotten much traction. This reddit comment goes into great detail about the history of private stock exchanges in bitcoin, which might provide useful context:
Edit: Also this previous SX Bitcoin thread might answer your question: Can I buy stocks with Bitcoin?