The two outside directors of the National Bank of Georgia, appointed by federal regulators to investigate the bank's financial operations while Bert Lance was chairman, were misled about loans to the Carter family peanut warehouse operations, according to sources here and in Georgia.

The directors, Lindsey Hopking III and Church Yearley, relied mainly on information supplied to them by one former loan officer of the NBG. But it is not clear whether the bank itself had been misled or by whom.

The directors did not have access to Carter warehouse records, and many of the bank's own files were incomplete on some of the Carter warehouse loans.

For the past week, FBI agents have subpoenaed records from the Carter warehouse in Plains, Ga., and Arthur Andersen & Co., the bank's auditor. When these records are reviewed, Assistant Attorney General Philip Heymann, who authorized the present investigation, must decide whether to empanel a grand jury to review the Carter matters.

In a related development, Justice Department attorneys are preparing a memo on whether to seek indictments from the Atlanta grand jury, which for nearly a year has been hearing testimony about Lance's financial affairs. The grand jury convenes again in three weeks, at which time the prosecutors could be ready to seek indictments from it.

The two outside directors prepared a report as part of the settlement of a suit brought last April against Lance and the NBG by the comptroller of the currency and the Securities and Exchange Commission.

The report reviewed the terms of $6.4 million in loans to the Carter warehouse operation, beginning in 1975, that were arranged by Lance.

Investigators believe that the two directors were misled about what the Carter operation did with some of a $5.5 million line of credit. The loans eventually were paid off in 1978.

In particular, the federal agents are trying to determine what happened to these funds between November 1976 and August 1977.

The bank supplied the two directors with very little documentation on the loans for that period. The report says, however, that in the spring of 1977 Billy Carter was overdrawing his account to pay off the loans.At Lance's direction, those checks were not returned to Carter.

On June 7, 1977, the report says, "the situation had become serious enough for the loan officer to write Billy Carter, 'At this time we are holding appoximately $400,000 in warehouse releases with no funds to cover these releases."

There have been questions about whether any of the money lent to the warehouse was diverted to the Carter presidential campaign.

The White House has dened this and so has President Carter's trustee, Atlanta attorney Charles Kirbo.

The two directors in their report said: "We have seen no evidence that the proceeds of these loans were, at least to the knowledge of anyone at NBG, used outside the Carter peanut business."

But the federal probers -- with subpoena power unavailable to the two directors -- now are questioning the accounting on these loans.

Several sources say that Justice Department attorneys came upon the Carter loans while reviewing NBG documents subpoenaed by the SEC during its probe of Lance's affairs.

As for the Lance grand jury, if the prosecutors decide to seek indictments, they must first get approval from the administration. Reportedly, the prosecutors are preparing a memo to seek such approval.

The memo would spell out alleged criminal acts that have come to light as a result of grand jury questioning.

A three-man panel, established by former deputy attorney general Peter Flaherty to screen findings in the Lance case, will review the memo.

This panel will then report to Heymann, who can either accept or reject the findings of the memo. He can also buck the decision up to Deputy Attorney General Benjamin R. Civiletti.

According to a Justice Department spokesman, Attorney General Griffin B. Bell, who is a long-time stockholder of the NBG, has said he will not participate in any decision on Lance's banking activities.