I have written previously, as have numerous other investment managers, that in order for Citigroup (C) to have the best chance of being nimble enough to grow and be managed efficiently it needed to be broken up. The vast number of businesses they have, coupled with the dozens of countries they conduct business in, would make it extremely difficult for anyone, including current CEO Vikram Pandit, to successfully manage the company.

It now appears we are a day or two away from hearing from Citigroup that they are contributing their Smith Barney retail brokerage division to form a joint venture with Morgan Stanley's retail business. The combination would have more than 21,000 brokers, making it the largest brokerage firm in the world.

Although a dramatic shift from prior assurances from Citigroup CEO Vikram Pandit that he would not break up the company, I think this joint venture makes a lot of sense from their perspective. Under the rumored terms of the deal, Morgan Stanley would own 51% and manage the joint venture. Citigroup would own 49% and receive a ~$2.5 billion equalization fee (to account for the fact that Smith Barney has more brokers than Morgan Stanley).

Initial press reports had Citigroup selling 51% for $2.5 billion, which made little sense since it would only value the unit at about $5 billion. However, it appears they are getting $2.5 billion in cash and a 49% stake, which sounds more like it. In addition to the cash, Pandit downsizes Citigroup and makes his job of managing it a whole lot easier.

While this deal does not put an exact dollar value on Smith Barney (the joint venture will not trade publicly), which would have helped Citigroup shareholders more easily justify the current $6 stock price, it does give Morgan Stanley the option to buy out Citi's 49% stake in the future. While I would not suggest Citigroup sell the entire thing (it is doing far better than their banking businesses), this deal does manage to raise capital and make the large bank more manageable.

While not a life saver, this deal does make some sense, which is more than we can say about Citigroup's business decisions in recent memory.

Full Disclosure: No position in Citigroup or Morgan Stanley at the time of writing, but positions may change at any time