Morgan Stanley is rumored to be seeking a controlling stake in BlackRock from PNC Financial, a deal that, if completed, would create one of the industry's largest money managers. Spokesmen for Morgan Stanley, BlackRock and PNC declined to comment on the speculation of a deal, which was first reported today by cable television network CNBC. A union between Morgan Stanley and BlackRock, which has 70% of its publicly traded stock held by PNC, would create a firm with $884 billion in assets under management. "It's a potentially landscape-changing deal," said Eric Fitzwater, a senior analyst who covers asset management for investment bank SNL Financial. "It would catapult Morgan Stanley to a completely different league."