The Hughes administration and legislative leaders have reached agreement on a plan to ease prison crowding by shifting up to 700 state prisoners to local jails, building a 300-cell "super maximum" security facility in Hagerstown and planning another prison to hold as many as 1,440 inmates.

A key component of the plan is an agreement between the state and Baltimore to shift the proposed "super maximum" prison from the city and donate the site previously earmarked for it, adjacent to the Maryland Penitentiary, to Baltimore for expansion of its city jail.

In turn, the city would accept at the jail hundreds of short-term state prisoners, provided the state pays part of the operating cost of the facility.

The plan hinges on passage of legislation pending in the House that would allow prisoners sentenced to a year or less to be housed in local jails. Currently, inmates serving more than 90 days must be imprisoned in state institutions. The legislation could add hundreds of inmates to the Baltimore jail and about 50 to the Prince George's County Detention Center.

The shift of the proposed "super maximum" prison to Hagerstown is supported by Gov. Harry Hughes, House Speaker Benjamin L. Cardin (D-Baltimore) and Senate President Melvin A. Steinberg (D-Baltimore County), according to legislative sources.

However, state Sen. Victor Cushwa (D-Washington) sharply criticized the proposal today, saying it is a "breach of promise" by Hughes and Cardin.

Cushwa said that both men had promised there would be no further prison construction in Hagerstown, which already has three state prisons. "We're screwed again because we don't have the votes," he said.

Other legislators said the plan represents at least a partial solution to the worsening problem of crowding in state prisons, which every month receive an additional 90 inmates.

There are now almost 13,000 prisoners in a system designed for 9,300 and portions of two of the largest institutions -- the House of Correction in Jessup and the penitentiary -- date to the 19th Century.

State prison officials have proposed a $50 million renovation for the penitentiary, and replacement of the House of Correction beginning in 1989.

Shifting the "super maximum" security prison to Hagerstown, where land prices and construction costs are less, would save the state about half the estimated $20 million cost of building it in Baltimore, and substantially reduce operating costs.

The plan to reduce prison crowding includes a proposal to allocate funds in next year's state budget to plan for either a 720- or 1,440-bed prison at an undetermined site. The state is now building a 1,500 cell prison in Somerset County on the Eastern Shore.

The Hughes administration had intended to formally unveil the plan today, but some members of the Senate leadership raised last-minute concerns about it. The plan was completed this week when Baltimore Mayor William Donald Schaefer met with Hughes and urged the state to relinquish the Baltimore prison site in exchange for the city's commitment to accept state prison inmates.

As part of the deal outlined in an eight-point memo, Hughes has agreed to establish a task force to study means by which the state could help local jurisdictions with the operating costs of their jails.