Four of Morgan Stanley's top research analysts and strategists have written a letter urging senior management to safeguard the firm's culture and values in a clash with dissident shareholders.

Although the letter doesn't take sides in the battle between Morgan Stanley Chief Executive Philip Purcell and the dissident alumni calling for his ouster, it was sent just before a board meeting April 30 at which directors adopted a series of responses to the crisis.

The letter was written to Zoe Cruz and Steve Crawford, the firm's newly installed co-presidents. The four signers were star Internet analyst Mary Meeker, investment strategists Byron Wien and Henry McVey, and chief economist Steven Roach.

Although the letter itself couldn't be obtained, three people who say they have read it described its contents in separate interviews. One person who was told of its contents said the person who gave it to Ms. Cruz asked her to share its contents with the firm's directors; it isn't known whether Ms. Cruz did so.

The letter urged Ms. Cruz and Mr. Crawford, who have spent time discussing the critics' claims with clients, shareholders, directors and the media, not to lose sight of the intangible factors that had made the firm great, the people said. The letter indicated that the values and culture had been damaged, one of those interviewed said.

Speaking for the signers at the behest of company management, Mr. Roach said in a statement the letter was written "in a positive and constructive spirit." A company spokeswoman didn't have any additional comment.

The signers were the first employees known to have expressed themselves on the record, albeit privately, to management during the conflict that has wracked the firm. Because of their stature on Wall Street, they would have less to fear than others about any adverse consequences from the letter.

On March 28, a group of alumni called for Mr. Purcell's ouster after he replaced the head of institutional securities, promoting Ms. Cruz and Mr. Crawford, and demoted two other executives who then left. The alumni accused him of promoting based on loyalty, and two senior bankers resigned two weeks later.

One area where Mr. Purcell and his deputies have taken steps that were perceived as counter to the firm's culture has been in dispensing so-called stay bonuses aimed at retaining top executives during the crisis.

Such retention bonuses had previously been awarded to top performers around year end in the form of company stock, to which the employees become entitled over a period of years.

Mr. Purcell himself personally played a role in offering retention stock awards in the first days after the management reshuffle to one or more senior bankers, according to people told of the actions.

But after initially accepting the awards, the same people said, some of the bankers reconsidered and changed their minds amid an internal outcry in which such awards were perceived as attempts to buy loyalty. The awards were offered to people in equities and mergers where the firm is strongest, the people said.

A person close to company management called the small number of accepted awards "a prudent thing to do at an extraordinary time," adding that less than half a dozen were actually offered and accepted. No new awards have been made in the past month, the same person said.

Some recipients disclaimed their awards after being asked to do so by others within the firm who felt the bonuses ran counter to the culture, according to people familiar with the events.