I will confess to being no expert when it comes to the asset management business. Still the sheer size of the Blackrock acquisition of Barclays Global Investors takes me aback.

For those not familiar already with the transaction, here is a recap from the WSJ:

BlackRock Inc. reached an agreement to buy Barclays Global Investors from Barclays PLC for $13.5 billion, creating a money-management titan roughly twice the size of its closest competitor.

The price represents a substantial premium to what analysts thought BGI would fetch and underscores how capital markets have revived in recent months. It represents a big payday for both Barclays and some of its executives.

The firm, renamed BlackRock Global Investors, will have more than $2.7 trillion in assets under management. The deal makes BlackRock, already a major player in actively managed stock, bond and alternative-investment products, an indexing giant and the largest U.S. provider of exchange-traded funds.

“This is a once-in-a-lifetime opportunity to put two firms together that have 80% or 90% complements and very little redundancy,” said Laurence Fink, BlackRock’s chairman and chief executive.

The transaction, expected to close in the fourth quarter, gives the British bank a 19.9% stake in BlackRock. Barclays President Robert E. Diamond and Chief Executive John Varley would take seats on BlackRock’s board. BlackRock is acquiring BGI in exchange for 37.8 million shares of common stock and equivalents and $6.6 billion in cash.

It seems like just a nano second or so ago, every blogger worth his salt was baying at the moon about giant financial institutions. No more “too big to fail” was the mantra. This morning, Felix Salmon is once again opining that $300 billion is the maximum size any bank should be allowed to attain. I don’t need to run throught the litany, you’ve seen and read all of the arguments.

So now this gargantuan combination of money managers and not a peep out of anyone. I mean it, not one voice of concern so far as I’ve been able to discover.

Look, I freely admit to not knowing beans about this business so help me out. Is it that risk free that there’s no reason to worry? Is it not even remotely possible that Blackrock could get into trouble and need a bailout? Are there better things to worry about?