WaMu Shares Continue Slide

Updated from 3:16 p.m. EDT

Washington Mutual (WM Quote) briefly hit a new 52-week low on Wednesday as concerns continue to mount about the big thrift's potential mortgage losses and the bank gets ready to convert certain preferred stock.

WaMu shares are down 50% since the bank announced a $7 billion capital injection led by private-equity firm TPG and other large investors in early April. But worse, the stock is down more than 20% just from Thursday's closing price, the day before a Wall Street Journal report that said regulators were probing another hard-hit bank from the housing downturn, National City(NCC Quote). The report, confirmed Tuesday by the Cleveland-based bank, has investors worried regulators are looking at other troubled banks.

The bank issued a statement late on Thursday saying that while commenting on market rumors was not its policy, "recurring speculation about regulatory activity" led it to act.

"Neither our primary federal regulator, the [Office of Thrift Supervision], nor any other bank regulatory agency has taken any enforcement action against WaMu that we have not previously disclosed," the statement read. "Further, the company is not currently in such discussions with any regulatory agency."

Much of the damage, however, had already been done. Shares of WaMu hit a new 52-week low of $5.75 at one point on Wednesday, as investors became even more jittery about the stock over potential losses and whether the bank would have to raise even more capital. Such concerns were amplified as news broke that Lehman Brothers(LEH Quote) may be looking for foreign investors, even after announcing plans to raise $6 billion through preferred and common stock offerings.