Shares of AOL Time Warner Inc. (AOL) tumbled 9 percent on Friday on concerns the world's largest media company may take another huge write-down of its assets and following reports that regulators may widen their probe of the company's finances.

The company took a $54 billion charge in the first quarter -- the largest ever -- to write down the value of America Online's acquisition of Time Warner. Analysts have said more write-downs could come, resulting in another large charge next year.

Shares closed at $12.76, down $1.31, after falling as much as 11 percent earlier on the New York Stock Exchange.

The company attributed the first-quarter write-down to the decline in stock value of Time Warner between the time the deal was announced in January 2000 and the time it closed a year later.

"If the stock price was the cause of the last write-down, the market is asking, Is it judicious to assume that there will be another one?" said Gerard Klauer Mattison analyst Jeffrey Logsdon. "It's not unreasonable to make that assumption, if you apply the same logic. But it's also premature at this point."

AOL spokeswoman Tricia Primrose said, "It would be premature and inappropriate to take an impairment charge at this time." The review of such goodwill write-down will occur in the fourth quarter. "I'm not going to speculate on the results of that review," she said.

Since the year began, AOL Time Warner shares have fallen nearly 60 percent on concerns of slowing growth of its America Online Internet service, the company's difficulties in getting customers to pay for faster, more expensive Internet services, and federal investigations into its accounting practices.

The accounting probe by the U.S. Securities and Exchange Commission could be broadened into an investigation of insider stock sales while the company was making rosy earnings forecasts, the Financial Times reported in an unsourced story in Friday's issue.

"It certainly wouldn't be surprising to see the investigation widen in this direction," Logsdon said. "When you see stock sales compared to those early estimates, it's a fair question to ask, Who knew what and when?"

Primrose said the company was fully cooperating with the SEC's investigation and declined to comment further.

The company lost credibility on Wall Street in September when it lowered revenue and cash flow targets long after many of its peers acknowledged that an industry-wide advertising slump would hurt their results. Logsdon noted that most Wall Street analysts had cut their expectations for AOL long before the company did.