THERE WAS a time when Maryland state lawmakers didn't worry much about their dealings with lobbyists. Exchanges of favors--above and below board--were a way of life. But as the stakes grew, so did public concern. Some ethics loopholes have been closed. Now a case involving a Baltimore delegate's dealings with a lobbyist has prompted House Speaker Casper Taylor Jr. and Senate President Mike Miller Jr. to propose a further tightening: a ban on business deals between legislators and lobbyists.

Their action follows the indictment of Del. Tony Fulton for helping lobbyist Gerard E. Evans, also charged, to defraud clients. Del. Fulton is charged with preparing sham legislation, a proposal that several of Mr. Evans's clients would want to have him working to defeat. According to the indictment, Del. Fulton never intended to push the proposal, only to stir up client business for Mr. Evans; the lobbyist steered a $10,000 real estate commission to the delegate. Mr. Fulton says he is innocent, that his real-estate commission and his preparation of the bill were unrelated.

During that session Del. Fulton did file a disclosure statement with the legislature's ethics committee about his involvement in the real estate transaction; and there the matter rested until the federal indictment.

Tighter legislation is needed to eliminate direct lawmaker-lobbyist business dealings. Regardless of the outcome of the Fulton-Evans cases, the ban makes sense and ought to be approved. (Normal business conducted between the part-time legislators and their contacts other than lobbyists would not be restricted).

The majority of today's lawmakers in Maryland have had no great problems accepting improvements in the ethics laws. On the contrary, members have noted that they welcome the measures as clarifications of their duties and as reassurances to the public. In that spirit, they should move this latest measure through the coming session.