Nearly a week since Facebook’s debut on the stock market, concerns continue to swirl around the social network and its underwriters. Peter Whoriskey and David S. Hilzenrath report:

It was just the kind of information that could make you a million. But you couldn’t find it on Facebook or, for that matter, anywhere else on the Internet.

In mid-May, as the social-networking company prepared for a public sale of its stock, an analyst at Morgan Stanley began advising clients orally that Facebook profits would probably be lower than previously estimated.

The fact that the analyst worked for Morgan Stanley, which was the lead bank arranging for the sale of the company’s stock, added credibility to his analysis. At just about the same time, other analysts working for banks affiliated with the sale similarly reduced their earnings estimates.

The investors who received and took note of these warnings may have saved lots of money: As many investors now know all too well, the value of Facebook stock rose briefly on its first day and has since plunged 16 percent from its original price.

Now federal regulators, shareholder attorneys and angry investors are looking askance at the hype — and company disclosures — that attended the lead-up to last week’s ballyhooed Facebook stock sale.

They want to know whether the company and the banks that arranged the sale pulled one over on ordinary investors, against whom the odds are often stacked in initial public offerings.

The Associated Press reports that Morgan Stanley, the IPO’s chief underwriter, is planning to make price adjustments for investors:

Morgan Stanley, the lead investment bank in Facebook’s troubled initial public offering, will compensate investors who overpaid when they bought Facebook’s stock in Friday’s IPO, according to a source familiar with the matter.

This person said the firm is reviewing orders its retail clients placed for Facebook stock, and will make price adjustments if the clients paid too much. The person spoke on condition of anonymity because they were not authorized to discuss the matter publicly. The person did not say what amount constituted overpaying for Facebook’s stock.

Beyond the action on Wall Street, Bloomberg News reports that the botched stock offering is having ramifications in Washington for Facebook’s lobbying operation:

Congressional questions about Facebook Inc.’s initial public offering are forcing its nascent lobbying operation to play defense before it builds the political support companies need before coming under scrutiny.

“They have not made the connections and personal relationships they would like to have made,” former Senator Byron Dorgan of North Dakota, a senior policy adviser at law firm Arent Fox LLP, said in an interview.

“I’m sure they’re going to be doing double duty trying to introduce themselves and at the same time answering questions about the IPO.”

U.S. House and Senate committee officials said yesterday their staffs are gathering information about the social networking company’s offering and that the topic may come up at congressional hearings.

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