When it comes to describing how many Wall Street firms operate, some expressions seem perfect.

Like "smoke and mirrors."

According to The Phrase Finder, it's use as a label for trickery or deception can be traced back to journalist and author Jimmy Breslin, who once described political power as an illusion conjured up through "mirrors and blue smoke."

Nowadays, however, the expression seems best suited to describing the dubious lengths that struggling financial institutions are going to in order to "prove" that they are healthy and that all is well.

In "Banks Find New Ways to Ease Pain of Bad Loans," the Wall Street Journal's David Enrich details a few examples of this farcical charade.

In January, Astoria Financial Corp. told investors that its pile of nonperforming loans had grown to about $106 million as of the end of last year. Three months later, the thrift holding company said the number was just $68 million.

How did Astoria do it? By changing its internal policy on when mortgages are classified on its books as troubled. The Lake Success, N.Y., company now counts home loans as nonperforming when the borrower misses at least three payments, instead of two.

Astoria says the change was made partly to make its disclosures on shaky mortgages more consistent with those of other lenders. An Astoria spokesman didn't respond to requests for comment. But the shift shows one of the ways lenders increasingly are trying to make their real-estate misery look not quite so bad.

From lengthening the time it takes to write off troubled mortgages, to parking lousy loans in subsidiaries that don't count toward regulatory capital levels, the creative maneuvers are perfectly legal.

Yet they could deepen suspicion about financial stocks, already suffering from dismal investor sentiment as loan delinquencies balloon and capital levels shrivel with no end in sight.

"Spending all the time gaming the system rather than addressing the problems doesn't reflect well on the institutions," said David Fanger, chief credit officer in the financial-institutions group at Moody's Investors Service, a unit of Moody's Corp. "What this really is about is buying yourself time. ... At the end of the day, the losses are likely to not be that different."

Still, as long as the environment continues to worsen for big and small U.S. banks, more of them are likely to explore such now-you-see-it, now-you-don't strategies to prop up profits and keep antsy regulators off their backs, bankers and lawyers say.

At Wells Fargo & Co., the fourth-largest U.S.