The attorney general's office succeeded Tuesday in cracking a nugget of what it says is a big problem in Maryland - the alleged practice of small shopping center landlords restricting competition by agreeing with certain tenants that only one type store, such as a grocery store, will be in each center.

Francis B. Burch, Maryland's attorney general, said a consent decree involving a small shopping center in Carroll County, "sets an important precedent for the leasing of shopping center space throughout the state."

He added that he expected the new agreement, which is the first application of Maryland's antitrust law on a small shopping center, to have a chain reaction which would result in "lower prices and a greater selection of products" in such shopping centers.

In the Carroll County situation, the landlord of the North Carroll shopping Center allegedly agreed with Super Thrift, a grocery store and Sav-a-lot Inc., drug stores, not to rent space to other drugs stores or grocery stores.

Last Nov. 18, Burch filed the antitrust suit against the shopping center.

The consent agreement, which was filed with the circuit court for Carroll county, involves only P.A. & S. Small Company, a Pennsylvania Corporation with several grocery stores in Maryland trading under the name of Super Thrift. The agreement prevents the company from entering into any "understanding" for the next 10 years with the owners of the North Carroll Shopping Center that would prevent competitors from leasing space.

A lawyer for the P.A. & A. Small Company could not be reached for comment.

Robert Zarnock, an assistant attorney general, said the attorney general's office is close to accepting similar consent agreements with the owners of the shopping center.

The full suit is still pending against Sav-a-lot Inc.