New York Community Bank, the lender reeling from mounting real estate-related losses, shared several bad news Thursday: Its fourth-quarter losses were $2.4 billion worse than it had previously reported; its CEO and an allied board member are out; and the bank has identified what it called “material weaknesses in internal controls.”

The joint disclosures, released in securities filings late Thursday, were an uncomfortable reminder of the price the bank is paying for a breakneck expansion strategy that included the acquisition of an ailing rival less than a year ago. They sent the bank’s already pressured shares into another tailspin, with a drop of more than 20 percent in after-hours trading. The stock had already fallen 54 percent this year.

The unpleasant developments were the last thing NYCB needed after weeks of trying to calm investor concerns about its financial health. For weeks, questions have been raised about the depth of its losses on investments and loans tied to both office and apartment buildings, an area of ​​concern for banks generally, but one on which NYCB has particular focus.

Despite its name, the bank has a national presence, in part due to its acquisition of much of Signature Bank, which collapsed during last year’s banking crisis. Headquartered on Long Island, NYCB operates more than 400 branches under brands including Flagstar Bank throughout the Midwest and beyond. Flagstar is one of the largest residential mortgage servicers in the country, making the bank particularly at risk from any weakness in the housing market in an era of persistently high interest rates.

In January, NYCB surprised investors and its peers when it unexpectedly posted a fourth-quarter loss of $252 million, cut its dividend, and set aside a significant amount of reserves to cover any future losses. NYCB’s disclosures on Thursday mean it took an additional $2.4 billion impairment for the fourth quarter.

The bank’s woes are resurfacing year-old fears about how small lenders have been weathering the sharp rise in interest rates since March 2022, although NYCB’s disclosure last month did not trigger a widespread liquidation.

Last spring, Silicon Valley Bank’s financial health problems triggered an exodus of depositors that ended with its collapse as customers withdrew their money. That spooked investors at other banks that had large chunks of deposits that weren’t protected by the Federal Deposit Insurance Corporation, which backs accounts up to $250,000.

When the dust settled, three banks had failed, including First Republic Bank, which was the second-largest U.S. bank collapse by assets. Silicon Valley Bank was sold to First Citizens Bank, Signature to NYCB and First Republic to JPMorgan Chase.

NYCB had $83 billion in deposits and more than $100 billion in total assets as of this month. Documents filed Thursday did not provide more recent figures and a spokeswoman did not respond to a request for comment.

The extent of the bank’s problems (past and future) remains unclear. Its new disclosures said its “controls and procedures and internal control over financial reporting were not effective as of December 31, 2023” and the bank promised future updates.

The bank’s new CEO, Alessandro DiNello, was named executive chairman of its board this month. DiNello, who ran Flagstar before it was purchased by NYCB in 2022, replaced Thomas R. Cangemi, who had been with the company for nearly three decades. A board member who did not support DiNello’s appointment as CEO resigned around the same time.