Yahoo (YHOO) calls are seeing early action Monday. Bloomberg reported that, after Yahoo let the merger deadline pass without agreeing to a deal, Microsofts Balmer is weighing the possibility of fighting to oust Yahoos Board and pave the way for a takeover. The offer expired over the weekend. Meanwhile, Reuters noted that Google (GOOG) thinks that regulators would not move to bar a potential business deal with Yahoo because it falls short of an outright merger. It would be non-exclusive. 18,000 YHOO calls have traded, more than double the number of puts. With the stock down 10 cents to $26.70, most of the action is in the May and June 30 calls.