In a move to make it one of the largest retail brokerage operations in the country, banking giant Wachovia (NYSE: WB) has bought AG Edwards (NYSE: AGE). The combined operations will become second only to Merrill Lynch (NYSE:MER), and ahead of Citigroup's Smith Barney. The new operation should have about 15,000 brokers.

It is easy to say that the move is simply a cost consolidation play. Wachovia says that it can take out [subscription required] about $400 million in duplicate costs, which should add to the profitability of the acquired assets.

Wachovia, however, is cleverer than simply making the purchase as a simple earnings play. Retail brokers are huge collectors of assets. The new, combined operation will manage $1.1 trillion.

Rival banks, including Bank of America (NYSE: BAC) and JP Morgan (NYSE: JPM) do not have networks of brokers anywhere near this scale. That gives Wachovia an edge in wealth and asset management that Citigroup already has. While Wachovia's stock is flat over the last year, Citi is up about 12% and JP Morgan has climbed well over 20%.

Perhaps Wachovia needs a little edge.

Douglas A. McIntyre is a partner at 24/7 Wall St.