Bethesda-based Suburban Bank, Maryland's fourth largest, has decided to follow the path of the state's three biggest banks and move its credit card operations to Delaware.

Suburban board chairman Robert F. Tardio made the decision last night, after the House of Delegates voted to retain a rule that forbids banks and retail merchants from charging membership fees for credit cards.

Gov. Harry Hughes said today he will seek to have the House's decision reversed in the Senate, but banking interests hold little hope that the prohibition will be removed. The threat of banks moving their operations out-of-state was one of the factors that led Hughes and Attorney General Stephen H. Sachs to reverse positions they took last year against interest rate deregulation and credit card fees.

The powerful banking lobby has stressed repeatedly that interest-rate ceilings and restrictions on fees are denying legitimate profits to banks and lending institutions, and that consumers are suffering because less credit is available.

The House vote Wednesday, seen as a major victory by consumer advocates, was on an amendment to a controversial bill that would allow state-imposed ceilings on interest rates to rise from 18 percent to 24 percent on most consumer loans and credit card charges. The bill will be up for a final vote in the House within a few days.

Suburban Bank officials had been considering the move to Delaware, which permits credit card fees, since last summer, and gave no assurances to state officials that they would retain credit card operations in the state even if membership fees were approved. But William K. Weaver, executive director of the Maryland Bankers Association, said Suburban would have stayed in Maryland if the fees had been approved.

Legislators who were against allowing the fees, however, argued that banks were going to move their operations out of state regardless of what action was taken in the legislature.

Suburban, which is part of a $1.7 billion holding company with 68 branch offices in Maryland, employs about 100 persons in its credit card division.

Maryland National Bank, which began its Delaware-based credit card services earlier this month, employed 250 persons at its Baltimore offices and is the largest of the four banks leaving the state.

The other two are First National Bank and Equitable Trust, both of which are located in Baltimore.

"The thing that concerns me is that it charging fees is happening all over the country," Hughes said at a press conference this morning. Maryland is one of 19 states that prohibits credit card fees.

"I can see that the end result will be that Marylanders will not be able to get a credit card in Maryland and will have to pay a credit card fee anyway ."

Hughes said the fees--$18 a year is what Maryland National will charge--are "fair" because they would be deducted from finance charges now paid by 60 percent of all credit card holders. Hughes said most persons paying finance charges have small incomes and were effectively "subsidizing those who pay on time."

Maryland National and Suburban will use their Delaware bases for credit-card and other consumer credit services. First National and Equitable are only moving credit-card operations.

Franklin Goldstein, a lobbyist for Citicorp, which employs some 600 persons at its CHOICE credit card headquarters in Towson, said today the firm would delay a decision on relocating its three-year-old operation until the legislature completes action on the interest-rate bill.

"There is no real magic to this. It's a question of competition," Goldstein said. "If you give us the ability to compete and make a legitimate profit, we think we will stay in Maryland. The real question is whether we can make money here."

Weaver said that only nine of the state's 99 banks issue credit cards, and that the four largest banks issue approximately 85 percent of them. Banks, however, issue only about 200,000 of the one million cards held by Marylanders.

The five other banks that issue cards are likely to remain in Maryland, Weaver said, because they can not justify the expense of moving. Although the four big banks expect to lose about 20 percent of their credit card customers, Weaver predicted that the smaller banks that stay will not pick up new cardholders.