The head of TD Ameritrade (AMTD) today indicated that his firm might have an interest in buying troubled discount broker E*Trade. AMTD might get quite a deal "We like their retail business but we must figure out a way that makes sense for both sets of shareholders," the AMTD told CNBC according to a report at MarketWatch. Could E*Trade's brokerage clients be separated from it banking unit? The mortgage-related problems in he company's banking business are what caused the large write-offs that have taken ETFC's shares down. TD Ameritrade currently has a market cap of $11.6 billion to E*Trade's $2.3 billion. If ETFC could spin-off the brokerage business and merge it into AMTD, it might have a valuable asset to give its shareholders--TD Ameritrade shares. But, it would take a fair amount of financial engineering to set the banking business up on its own. Its value in the market is probably nil. But, if E*Trade's troubles continue, moving its shareholders into AMTD stock might be the safest haven the company can find for them.