The former finance director for the city of Rockville pleaded guilty yesterday in Montgomery County Circuit Court to convering nearly $84,000 in city funds to his own use during the past three years.

Evan Lee Brott, 38, was accused of embezzling more than $204,000 from thie city. Brott obtained about half of this total by depositing checks drawn on the city's operating account into the bank account of a dummy company, Deputy States's Attorney Timonthy Clarke charged during yesterday's court session.

Clarke said in court that the city has recovered all but about $85,000 of the funds.

The embezzlement was discovered last spring during a routine audit by the Arthur Anderson & Co., auditing firm, Clarke said.

The prosecutor said the auditors discovered 13 checks totaling about $102,000 written to the D&B Co. beginning in October 1976, a few months after Brott had been appointed finance director.

In each case, a form had been presented to the city of Rockville for payment for "services rendered" by the company, but no services were ever specified and, in fact, the company did not exist, Clarke said.

The initials "E.B." appeared on the authorized signature line on each form, he said.

Checks drawn on the city account then were deposited in a D&B Co. bank account, over whihc Brott had control, Clarke said.

The prosecutor said that on May 9, after Brott was notified about the audit, he depositied in four savings accounts checks totaling another $102,000 written by Brott and made payable to himself.

Brott's lawyer, James R. Miller said the money was used "basically to pay bills, bank loans . . . and medical bills." Miller said he would have more specifics on how the money was used when Brott is sentenced in about two months by Circuit Court Judge William M. Cave.

Brott pleaded guilty to five counts of fraudulent misappropriation by a fiduciary, which Clarke said is a form of embezzlement. The maximum penalty is five years in jail for each count.