CHICAGO (AP) _ Cook County Jail is so overcrowded that authorities have been forced to release 50 to 60 prisoners a day on recognizance bonds, including some charged with felony theft, officials said.

On an average day, about 90 prisoners must sleep on mattresses on floors and the jail has a shortage of guards, officials said.

Robert Glotz, director of security, said the early release of suspects means that the bonds set for them by judges are being ignored.

''This is the worst crowding we've had since 1982, and it won't be too long before the overcrowding hits our maximum-security section,'' he said.

Glotz said the jail's capacity is 5,500 prisoners.

''Pretty soon I will be at the point of having to release prisoners charged with more serious felonies, and I wouldn't want to do that,'' Glotz said. ''The only felons that are being released now are those charged with theft.''