ROME, Ga. (AP) _ An FBI expert has matched a leaked copy of a bank examiner's report criticizing former federal budget director Bert Lance's Calhoun First National Bank with a copy held by one of the bank's directors.

The FBI expert's conclusion was disputed by a lawyer for Lance, who has filed suit charging that someone in the U.S. Office of the Comptroller of the Currency leaked the report to an Atlanta newspaper reporter.

The comments from both sides are in documents filed in U.S. District Court in Rome by Assistant U.S. Attorney Myles E. Eastwood.

Eastwood said one page of a copy of the report retrieved from a bank director had underlinings matching a page in the copy mailed anonymously to Peter Mantius, a reporter for the Journal and Constitution.

Eastwood asked Lance, Calhoun First's chairman, and the bank to drop the lawsuit against the comptroller's office. The documents include a reply from Lance attorney Anthony L. Cochran, who said Lance's suit also alleges that the comptroller's office violated its confidentiality requirements by mailing the report to individual bank directors, rather than just to the bank.

Cochran's letter said Lance ''vigorously denies and contests'' the conclusion that a director leaked the report, but added, ''Even assuming that the government's expert opinion is correct that one of the directors leaked his copy of the report, ... that only aids in establishing that the OCC put the instrument and opportunity for the leak in the hands of that director.''

Lawyers on both sides declined comment on the court documents Thursday.

The bank examiner's report criticized practices at the north Georgia bank, claiming Lance, first budget director of President Carter's administration , engaged in ''violations of the law'' and ''unsafe and unsound banking practices.''

The comptroller later sued Lance and First Calhoun, charging Lance kept the bank's shareholders in the dark about the progress of merger talks with First Railroad and Banking Company of Georgia.

Charles Presley, chairman of the Augusta-based bank holding company, said in September that plans for a merger were dropped because of the ''controversy, claims and counterclaims'' about Lance and First Calhoun.

He said merger talks might resume after the bank's differences with the comptroller are resolved.