Here’s a summer quiz: Identify the following two US banks:

1. This institution has been profitable throughout the credit crisis. Last year, it reported net income of $6bn on revenues of $60bn, despite taking big hits in its consumer operations in North and South America in the fourth quarter. At the end of the first quarter the bank had total assets of $958 billion, supported by a healthy deposit base of $660 billion.

2. The second institution lost a massive $36 billion last year. Even net revenues were negative to the tune of almost $7 billion. This bank had a $662 billion balance sheet at the end of the first quarter, but deposits of just $88 billion.

The answer: they’re both Citigroup.

If anyone was still wondering why Vikram Pandit is planning to split the ailing megabank in half, Citi’s restatement of its historical financial data provided the answer.

Citicorp, which includes the retail, commercial and transaction banking businesses, is a financial powerhouse. Citi Holdings, which owns the consumer lending and brokerage businesses - as well as a huge pile of toxic assets - is a financial dumping ground. No prizes for guessing which half Pandit will be focusing on when Citi reports second-quarter earnings on July 17th.

Unfortunately for shareholders, shortly to include the US government, the split is pretty meaningless. No matter how well Citicorp performs, it will count for little as long as it’s still attached to Citi Holdings. If these figures are any guide, the two will be conjoined for a very long time.