The Maryland House of Delegates today, in a move designed to increase the influence of Southern states in the selection of presidential candidates, overwhelmingly approved legislation that would change Maryland's presidential primary from May to March.

The 76-to-53 vote was for final passage, because the Senate has already approved the bill. But opponents of the measure, which would allow Maryland to join Virginia and six other Southern states in a so-called "Super Tuesday" primary on the second Tuesday of March, moved almost immediately to have the vote reconsidered. The vote on whether to reconsider is scheduled for Saturday.

Sponsored by Sen. Thomas V. Mike Miller Jr. (D-Prince George's) and Senate President Melvin A. Steinberg (D-Baltimore County), the measure is part of a movement by some Democratic strategists to persuade the 15 Southern states to hold their primary on the same day. They believe this Southern regional primary day will aid the more moderate to conservative candidates favored by Southerners, who Miller and others believe will be more successful in national contests than their liberal counterparts have been.

As the General Assembly rushed to complete its work by the Monday adjournment, members of a House panel, continuing a rebellion that began earlier in the week, threatened to kill a landmark savings and loan reform bill and won a key concession when conferees agreed to a provision for additional disclosure of some thrift withdrawals. Details on Page B1.

In other action today, key House committees approved a bill to legalize slot machines on the Eastern Shore and agreed to allow the full House to vote on a measure to strip a tax break from the exclusive Burning Tree Club in Bethesda.

And Gov. Harry Hughes, in a surprising, last-minute reversal, told legislative leaders today that he will support a measure that would dramatically increase state aid to local schools if lawmakers agree to delay implementation of the bill for another year.

Hughes has opposed the controversial education aid measure since it was introduced by House Speaker Benjamin L. Cardin (D-Baltimore) weeks ago, with the governor arguing that the $300 million, five-year program should be approved by the next administration.

But Hughes' chief budget officer told the General Assembly's top legislative leaders, who were meeting to discuss the substantial differences between the House and Senate versions of the bill, that Hughes will support the measure if amendments are added that delay implementation until 1987 and guarantee that the increases will go into effect only if sufficient revenue exists.

Hughes' reversal could improve chances for passage of the measure, which is regarded by many here as Cardin's legacy as he embarks on a congressional bid after 20 years in the legislature. But the measure has faced stiff opposition from the state Senate.

Later today, as delegates and senators continued working to clear their desks, the House approved the Southern regional primary bill over the objections of many lawmakers who said the measure would do nothing to enhance Maryland's current status as a minor factor in the presidential primary election process.

"Maryland won't get the attention that Florida and Texas get," said House Majority Leader Donald Robertson (D-Montgomery). "This may be a step to a series of regional primaries in which Maryland would become even less important."

But supporters of the measure said that the shift in emphasis away from early elections in other states will only help Maryland.

"This brings the primary process to the point where legitimate Democrats have an important early stake in selecting the president, not a handful of people in Iowa living rooms or New Hampshire, which is a Republican state," said Del. Gerard Devlin (D-Prince George's).

But the idea of regionalizing the election process troubled other lawmakers like Del. Nancy Kopp (D-Montgomery). "I question whether we want to end up with a system that produces a Southern candidate, a Northern candidate, a Midwestern candidate and a Western candidate," she said. "Sectionalism is not the way to go."

In other developments today, the House Judiciary Committee approved 10 to 6, with four not voting, a measure to permit Eastern Shore charities to own and operate slot machines if a percentage of the proceeds is donated to charity. The measure, which the assembly approved last year only to have it be vetoed by Hughes, set off a last-minute lobbying campaign by Hughes' aides, who told some lawmakers that Hughes would rather not have to veto the politically sensitive bill in an election year.

In another key House committee action, opponents of a measure that would end an $186,000 tax break for the all-male Burning Tree Club in Bethesda said they gave up their battle to kill the bill after Cardin intervened.

The measure, which passed out of the House Ways and Means Committee on a 13-to-9 vote Thursday, was sent today to the full House for action after veteran opponent Del. Paul Weisengoff (D-Baltimore) and committee Chairman Tyras Athey (D-Anne Arundel) abandoned an effort to keep it from the floor long enough to allow it to die during the waning days of the session.

"I would resist amendments and will not do anything to interfere with the committee bill as it makes its way through the House," said Weisengoff.

Cardin predicted that the measure will now be successful.

But at today's meeting of the Ways and Means Committee, opponents of the measure vowed to introduce legislation next year that would end state tax breaks for single-sex educational institutions as well.

"I hope you will support the legislation that will be introduced to make coed institutions out of Goucher and Hood colleges," Athey told the Burning Tree bill's victorious backers.

Del. Mary Boergers (D-Montgomery) said she would be happy to do so "as long as the Elks and the Moose are included too."