Meredith Whitney, the Oppenheimer & Co. (OPY) analyst famous for her prescient financial sector calls during the ongoing banking crisis, has downgraded Wachovia Corp. (WB) to “underperform,” saying prospects are “bleak” for shareholders of the Charlotte-based commercial bank.

Whitney slashed her rating on Wachovia to ‘underperform’ from perform in a research note, as she predicts a $1.35 per share loss this year and a 35 cent per share loss in 2009. She also noted that the bank likely reduced its mortgage portfolio by $50 billion in the second quarter.

“We are hard pressed to find examples of financial companies that have successfully shrunk their businesses,” Whitney said, speaking of Wachovia’s asset reduction, Reuters reported.

Wachovia shares dropped after Whitney’s prediction, and were trading at $9.60 at 12:30 p.m. in New York.

Wachovia shares are down nearly 75% year-to-date as the struggling commercial bank has already raised $8 billion in additional capital and cut its dividend in an attempt to help offset the $13.7 billion in losses the bank has taken since the current financial crisis started to unfurl. Wachovia has also ousted its chief financial officer, replacing Ken Thompson with Robert Steel, a former undersecretary of the U.S. Treasury Department.

Whitney: One to Watch

Whitney’s Wachovia call is big news, in part because the Oppenheimer analyst has made quite a name for herself with her bearish, but highly accurate, calls on the global financial sector. Previous Whitney predictions that have come to pass include her accurate claim that Citigroup Inc. (C) would be forced to slash its quarterly dividend, despite repeated management promises, prior to installing Vikram Pandit as CEO, that Citi’s dividend was safe.

Even with $416 billion in losses and write-downs tied to mortgage-backed assets in the global financial industry thus far, Whitney sees more trouble ahead for the beleaguered financial sector.