Prince George's County, facing "severe overcrowding" in the county jail, has asked Maryland officials to remove immediately at least 50 of the state prisoners held there under an agreement signed two years ago to help alleviate overcrowding in the state prisons.

The director of the county Department of Corrections, Arnett W. Gaston, sent a letter last month to Maryland officials, complaining that the county is holding 50 more prisoners than the 175 specified in the contact.

"State inmates are spilling over into uncontracted areas because they cannot be accommodated in the contracted housing confines . . ." Gaston said in his letter. "To continue to operate in this fashion jeopardizes our ability to provide all essential services and places us in violation of state, federal and local mandates. The state must take at least 50 inmates right away."

Under the 1977 contract, Prince George's County is to provide facilities for 175 state prisoners; but currently the county is holding 225. Besides the immediate reduction, Gaston requested that the state also remove another 50 prisoners in the future and increase its expense money paid to the county for each prisoner.

"We're already having problems findings segregated space for prisoners with behavioral problems or mental deficiencies," Gaston said in an interview yesterday. "If we don't get some help with this problem, we may have some complications."

Gaston said the jail, which currently holds 530 prisoners, is so full it has little room for recreational facilities.

The state has not responded to the county's request.

We've been out between the hammer and the anvil," Gaston said. "The state is aware of our problems, but this is just the first formal step in the process. No one knows what the final outcome will be."