Washington Mutual, one of the nation's biggest mortgage lenders, has often seemed like a cork during the credit storm.

Afloat, yes, but bobbing in a uncertain direction, driven by forces beyond its control. For months, it was viewed as a near-certain takeover target, most likely by J.P. Morgan Chase. That changed, of course, when J.P. Morgan swooped in to take control of Bear Stearns.

Now it may have found its mooring. Matthew Karnitschnig, Valerie Bauerlein, and Robin Sidel of the Wall Street Journal report that private equity heavyweight T.P.G. and other investors are nearing a deal to invest $5 billion in WaMu.  

The new capital is greatly needed. Last week, David Hendler, an analyst with CreditSights, estimated that if the value of WaMu's mortgage investments continued to deteriorate, it might need to raise another $5 billion to $6.2 billion of capital.

This investment in the last remaining shaky pillar of the mortgage industry should go a long way toward bolstering investor confidence. Following the Bear Stearns rescue, the Federal Reserve's moves to open the discount window, and the new capital being raised by other firms, one can be justifiably optimistic in thinking that the worst of the credit crunch is behind us.

The deal would also come just days before a contentious meeting of WaMu shareholders on April 15. A number of major shareholders have been critical of the performance of the nation's largest savings and loan and the steep drop in its stock price. Last month, it had its credit rating cut a notch by Standard & Poor's. In the fourth quarter, WaMu reported its first quarterly loss since 1997. Some investors are looking to shake up the board.

For T.P.G., formerly Texas Pacific Group, the investment is an usual one for private equity, which tends to stay away from regulated financial institutions with capital requirements.

Yves Smith on NakedCapitalism.com says it appears that private equity is stepping into the vacuum left by sovereign wealth funds, which last year took a number of big investments in U.S. financial institutions, apparently to their regret.

"So the T.P.G. move in theory is a positive development," Smith writes. "On the other hand if, like the sovereign wealth funds, they have merely acquired the right to lose money, T.P.G. and any 'me too' deals could be the last private sector hurrah before banks start resorting to more desperate measures (dividend cuts, asset sales despite the weak market for banking businesses, rights offerings)."