Business executives will be paying close attention to today’s announcement of new Justice Department guidelines for deciding when to indict corporations and company employees.

The new guidelines will provide assurances that prosecutors will not pressure corporations to turn over certain attorney-client communications, according to a letter to senators Leahy of Vermont and Specter of Pennsylvania from the deputy attorney general, Mark Filip, that outlines the expected revisions.

Mr. Filip will announce the changes today at the New York Stock Exchange.

Critics of the Justice Department’s existing guidelines for corporate prosecutions say prosecutors must be kept from considering a corporation’s willingness to turn over internal legal opinions when deciding what charges to bring, or whether to bring charges.

A pending bill in the Senate would forbid the Justice Department from using the disclosure of attorney-client material as an index of a company’s cooperation. Such a law could come under constitutional challenge.

Mr. Filip’s changes to the guidelines, which are currently called the McNulty Memo, are intended to head off support for the bill, which many prosecutors view as an effort by legislators to meddle in decisions that ought to remain, in their view, in the executive branch.

Despite the volume of discussion that the topic has generated among lawyers who specialize in corporate investigations, prosecutors in recent months appear to rarely request that companies turn over what legal advice they received from their lawyers. Before making such requests, prosecutors must receive the approval of the deputy attorney general. Mr. Filip wrote that in the preceding year and a half the Justice Department did not allow prosecutors to make any such requests.

The proposed guidelines are also expected to state that prosecutors will not look at whether a company is paying legal fees for employees in deciding whether to indict.