ORLANDO, Fla. -- Federal agents entered the Orlando, Fla., branch of financially troubled Colonial BancGroup Inc. on Monday with a search warrant.

Few details were released about what the agents were searching for or the nature of the investigation.

A spokeswoman for the inspector general of the U.S. Treasury's Troubled Asset Relief Program [TARP] said agents from her office, the FBI and Housing and Urban Development inspector general conducted a search on Monday.

"Due to the nature of the on-going investigation we cannot provide any further information," said the statement released by Kristine Belisle.

Colonial BancGroup maintains a bank branch and other offices at the location searched, company spokeswoman Merrie Tolbert said in confirming the search.

"The bank is cooperating with that search warrant," she said. "Colonial Bank continues to operate as usual in all locations and the search warrant has no impact on our day-to-day retail and commercial banking operations."

In its second-quarter report on Friday, the company said it was exploring several alternatives including a sale or merger of the company, selling off bank branches and seeking private capital. The company reported a quarterly loss of $608.3 million, or $3.02 per share, compared with a loss of $9 million, or 5 cents per share, a year ago.

The Montgomery, Ala.-based company is operating under orders from the federal government to maintain certain capital levels. It also recently suffered a financial blow when $300 million cash infusion from a stock purchase agreement fell through.

"As a result of the above described regulatory actions and the current uncertainties associated with Colonial's ability to increase its capital levels to meet regulatory requirements, management has concluded that there is substantial doubt about Colonial's ability to continue as a going concern," the company said Friday.

Shares fell 12 cents, or 20 percent, to close at 49 cents. The stock has steadily declined from a year-ago high of $10.50 and bottomed at 29 cents in March.

Colonial BancGroup operates 355 branches in Florida, Alabama, Georgia, Nevada and Texas.