The former Transportation Department employee charged with embezzling and spending $850,000 in federal funds in two months this summer was indicted yesterday by a D.C. federal grand jury.

William C. Sibert, 30, was charged with 18 criminal counts in connection with the alleged scheme to steal money by falsifying vouchers for federal transportation grants.

Sibert was arrested in July in Las Vegas. Nev, while carrying $59,000 in cash. Investigators said that they soon discovered he had been on a spending spree in which he purchased a new house, at least 14 luxury cars, stocks and bonds and a topless go-go bar here.

Since released on bond. Silbert was ordered arrested again after his indictment yesterday when Assistant U.S. Attorney Robert W. Orgen of the fraud division said the government believes Silbert is trying to sell some of the property he allegedly bought with stolen funds.

The Justtive Department has won a temporary court ruling that freezes Silbert's assets and prohibits him from disposing property. A Justice attorney said Silbert is believed to have entered the house he purchased in Clinton and to have removed some of the property in violation of the court order.

A hearing on the possible court order violation was scheduled late Thursday, but Silbert failed to appear. His attorney said Silbert's failure to appear was because of the short notice he had been given about the hearing, and did not constitute an intent to flee.