W. Dale Hess, convicted along with former Maryland governor Marvin Mandel on political corruption charges, was transferred yesterday from a U.S. prison camp in Alabama to a Baltimore prerelease center, where he will remain until his Jan. 13 parole date.

The transfer of Hess, who served more than 18 months at the Maxwell Air Force Base prison camp, leaves Mandel as the only one of the six defendants in the case who still is in prison.

In a last-ditch effort to gain his freedom, the former governor has asked President Reagan to order his early release from the federal prison camp in Florida where he is serving a three-year term. Mandel's lawyers also have filed a petition in federal court seeking Mandel's immediate release and asserting that the parole commission used inappropriate guidelines in his case.

The commission last year ordered Mandel to remain in prison until next May -- in essence serving almost his entire term, despite recommendations by federal prosecutors that he not be forced to remain imprisoned for the full period.

Hess left Maxwell before dawn yesterday and flew immediately to Baltimore, where he reported to a prerelease center run by the Volunteers of America, according to officials at the prison camp in Montgomery, Ala. The transfer is considered routine for prisoners within two months of parole.

The center, in a converted canning plant on Baltimore's waterfront, will be Hess's home until Jan. 13, officials said. Inmates there generally work outside the center on weekdays and may get 48-hour passes to go home on weekends.

Before entering prison Hess was a wealthy businessman, a vice president of Tidewater Insurance Associates and owner of a restaurant and motel near his Harford County home. He was convicted in 1977 on U.S. mail fraud and racketeering charges and was sentenced to three years in prison.