A district judge in Ireland ordered yesterday that fugitive Georgetown accountant Charles J. Walsh be extradited to the United States to face charges that he masterminded a tax-fraud scheme that cost the U.S. Treasury $6.8 million.

Dublin District Court Justice Lian McMenamin ordered the flamboyant Walsh, 37, who allegedly fled the United States shortly before his indictment last May, jailed immediately without bond.

In Washington, U.S. Attorney Joseph E. diGenova said Walsh is expected to request a bail hearing in the next several days pending "what we assume will be an appeal" of the extradition order to higher courts in Ireland.

Walsh was one of four U.S. fugitives taken into custody in December, one day after a new extradition treaty took effect between the two countries.

He later was freed on bond, but was rearrested by Irish authorities after a second indictment, charging another alleged fraud involving 118 investors who were bilked of about $600,000, was returned by a federal grand jury in the District of Columbia.

Walsh subsequently was freed again on bond until yesterday's hearing.

Paddy McEntee, an Irish lawyer representing Walsh, argued that Walsh could not be extradited under the new treaty for an offense in which the U.S. Internal Revenue Service was the only victim.

McEntee said American investors in a tax shelter plan offered by Walsh "did not mind one little bit" about losses they incurred when the plan allegedly turned out to be phony.

"They knew well that in return for their money they were getting tax shelters that only existed on paper," McEntee said.

Niall Fennelly, a lawyer representing the United States, contended, however, that all of Walsh's investors were tricked, including one who Fennelly said lost $460,000.

Walsh, now bearded, appeared in court looking relaxed and unworried during the 2 1/2-hour hearing. He has been living under his own name in a rented Victorian mansion outside Dublin since he left the United States.

According to the indictments, Walsh, the former head of a financial advisory firm in Georgetown, offered about 300 investors a plan involving leasing of mostly nonexistent marine shipping containers in return for tax credits and deductions.

The alleged scheme netted Walsh about $2.5 million, prosecutors charged.

The second investment plan involved transactions in securities, according to the indictment.