Allen & Co. Managing Director Dave Wehner is out pitching a LinkedIn venture capital round at a whopping $1 billion valuation, multiple sources say. This is a story we’ve been working on and isn’t fully baked yet, but VentureBeat started speculating about a potential buyout and so we’re going with what we have now.

Wehner is one of the senior guys at Allen & Co. and isn’t new to big deals – he supposedly led the sale of Bebo to AOL for $850 last month on behalf of Allen & Co. If it’s accurate that he’s pitching a LinkedIn round at a $1 billion valuation, it will be one of the most expensive private venture deals in recent history.

Like many investment bank led deals, the rumor is that this started off as an attempt to sell the company and moved to a funding round when there were no takers. Late last year TechCrunch UK reported that News Corp. may have been in talks with LinkedIn around an acquisition in that price range.

To date LinkedIn has raised $27.5 million over three rounds. They have said publicly they will reach $100 million in revenue in 2008.