Morgan Stanley & Co did the same, according to three advisers at the firm who declined to be named because they are not authorized to speak to the press. E*Trade Financial also stopped accepting orders as of 4 p.m. Eastern Tuesday, according to a client alert sent out that day.

Wells Fargo & Co's brokerage arm, Wells Fargo Advisors, stopped accepting new orders as of 4:00 p.m. EDT Wednesday, according to two advisers at the firm.

A Morgan Stanley spokesman and a Wells Fargo spokeswoman declined to comment.

Facebook is going public with almost a billion users, nearly $4 billion in annual revenue and a popular brand name.

On Monday Morgan Stanley, one of the 33 underwriters of the much anticipated IPO, told its advisers that it would cap the number of Facebook shares for each client at 500, according to four sources familiar with the situation. The goal is to make the shares widely available. But not everyone will get 500 shares, said the sources.

Some Morgan Stanley advisers with smaller accounts were surprised to learn they might have a chance to get shares for their clients, said one of the sources who is an adviser at the firm. Shares of popular IPOs would usually only be available to institutional investors and to top advisers who have sold IPOs in the past.

"It was a mad scramble," the adviser said. The adviser had less than two days to contact clients to see if they were interested in Facebook and go through the "extensive paperwork," the adviser said. The adviser said several clients did not get their paperwork in by the deadline on Tuesday evening.

An account alert sent out to E*Trade Financial Corp clients obtained by Reuters on Tuesday said the firm would no longer accept new conditional offers for the Facebook IPO as of 4 p.m. Eastern that day, though cancellation and modification of existing orders would still be permitted.

E*Trade was a last minute addition to Facebook's list of 33 underwriters. Officials at the online brokerage were not immediately available for comment.

Fidelity Brokerage, part of privately held FMR Corp in Boston, says it closed the offering period to qualified retail clients and registered investment advisers on Tuesday evening.

"The demand from customers is high," said Fidelity spokesman Stephen Austin. Fidelity has an exclusive retail distribution agreement with Deutsche Bank Securities, an underwriter in the Facebook deal.

(Reporting by Jessica Toonkel; Additional reporting by Jennifer Cummings, John McCrank, Joseph Giannone and Lauren Young; Editing by Gary Hill and Richard Chang)

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