State Senate leaders today sharply criticized elements of Citicorp's agreement with Gov. Harry Hughes and said it would destroy a fragile compromise designed to protect local financial institutions before the arrival of nationwide banking.

The senators are poised to decide the fate this week of Citicorp's bid for broad banking powers in Maryland.

"All the glitter has diminished" from Citicorp's offer to open a credit card service center near Hagerstown in return for the right to full banking privileges in Maryland by 1986, declared Senate President Melvin A. Steinberg (D-Baltimore).

Steinberg, a member of the governor's task force that hammered out a regional banking agreement with Maryland banks last year, said legislative approval of Citicorp's offer would "destroy that carefully negotiated compromise" on the regional banking pact.

Steinberg's comments marked the strongest legislative criticism to date of the agreement announced March 7 by Hughes and Citicorp, the largest bank holding company in the country. The criticism in part reflected a meeting that Steinberg held in Baltimore last week with leaders of Maryland's banking industry, the Senate president said.

"The concerns of the Maryland banks are valid," Steinberg said. "There are so many loose ends to the Citicorp agreement , so many questions."

Steinberg and other key senators echoed the harsh criticism by the Maryland Bankers Association, which contends the agreement violates a regional banking bill that is expected to reach the Senate floor later this week.

The pending legislation would permit banks in 12 southeastern states and the District of Columbia to purchase Maryland banks if those jurisdictions permit Maryland banks to purchase their banks. That system of regional banking would exist for four years, after which Maryland's borders would be opened to full interstate banking.

Steinberg, citing the regional banking proposal, gave the Citicorp agreement only a "50-50 chance" of passing a General Assembly that he said is unwilling to tamper with the compromise.

Meanwhile, aides to Hughes today reiterated the governor's strong support for the Citicorp deal and pointed to the bank's pledge to provide hundreds of jobs on the site of a former Fairchild Industries Inc. airplane plant in the depressed area north of Hagerstown. Hughes' agreement with Citicorp also includes a controversial provision requiring the state to "support Citicorp's position" if there is a legal challenge once the agreement is approved by the legislature.

Some observers said the Citicorp deal could get bottled up behind the logjam of bills in the waning days of the General Assembly, which closes in three weeks. House and Senate leaders already have given the interstate banking bill priority over the Citicorp proposal.