Gov. Martin O'Malley called for a "moderate" increase in public university tuition on Wednesday as state lawmakers gathered in Annapolis for the opening of a 90-day legislative session sure to be dominated by bleak financial choices.

The top task for lawmakers will be plugging a $2 billion hole in the state's roughly $13 billion operating budget, meaning they'll make the latest round of steep cuts in an election year.

The Democratic governor, who has prided himself on fulfilling his campaign promise to hold the line on college tuition increases, said the "brutal economy" and pressure by the university system and other state officials led him to believe the freeze should end.

Senate President Thomas V. Mike Miller, a Democrat, called it a "major concession" from O'Malley, who like all 188 state delegates and senators, is up for re-election this fall. Legislative analysts said a 3 percent tuition increase envisioned by the governor could save the state about $16 million.

Because the General Assembly must work from a budget plan submitted by the governor and generally only cuts from it, O'Malley's suggestion is almost certain to become reality. The governor is to unveil his spending proposal next week.

The battered budget colored the largely ceremonial first day in Annapolis, as lawmakers made typical -- and usually quickly abandoned -- pledges to work across party lines. Miller and House Speaker Michael E. Busch were re-elected to their leadership positions, the former for the 24th time and the latter for the 8th. Many lawmakers brought their families, and both U.S. senators gave pep talks.

In welcome-back remarks, Busch told lawmakers to brace themselves for "challenging times ahead."

Miller was more direct, saying budget items such as the Program Open Space land-preservation initiative, the heritage tax credit for renovating historic buildings, pet legislative projects funded through bond bills and funding for stem-cell research all warranted scrutiny.

His comments could foreshadow tough budget battles, since O'Malley has identified the heritage tax credit and land preservation as priorities.

"It is not a happy time at all," Miller said, describing the mostly somber feel of opening day. "There is no frivolity here."

Del. Anthony J. O'Donnell, the House minority leader, said his goal for the session is to "ensure that taxes are not raised now or in the future."

The Calvert County Republican said he's heard concern from scores of residents that the Democratic-controlled legislature won't increase taxes this year because of the election but will quickly do so next year.

O'Malley took top lawmakers by surprise when he raised the possibility of a college tuition increase during a morning radio appearance in Annapolis. Miller had said as recently as last week that he didn't believe O'Malley would unfreeze tuition in an election year.

"All good things have to come to an end," Miller said Wednesday. "If the state and the college system cannot afford another year with no tuition increases whatsoever, then common sense says 'allow a tuition increase.'"

Miller said he has been dismayed by cuts the college system has had to make to "merely keep the lights on." O'Malley said his goal had been to "restore affordability to college education" after his predecessor, Republican

Gov. Robert L. Ehrlich Jr., had "jacked up" tuition costs by 40 percent in four years.

"It's about balance, moderation and progress," O'Malley said, saying tuition rises that are in line with inflation and should keep Maryland's universities affordable. The governor said Maryland is the only state in the nation that can boast of a four-year tuition freeze.

The university system submitted a budget proposal that included a 5-percent tuition hike for fall 2010. The system's proposed budgets for previous years have also included tuition increases, but O'Malley regularly bypassed the request by increasing state spending on higher education.

William E. Kirwan, chancellor of University System of Maryland, was not surprised to hear that the freeze might be coming to an end.

"We've said all along that the state would not be able to afford to buy down the tuition forever," Kirwan said.

Clifford Kendall, chairman of the Board of Regents, who will have to approve any increase once the session is over, said O'Malley's decision reflects "tough times."

"It doesn't surprise me at all," Kendall said. "I think he's probably had to consider it seriously every year."

O'Malley aides have released few other details about the budget, which the governor called "pretty austere," apart from saying it adheres to the legislature's zero-growth recommendation. The governor also has indicated he will retain all of the cost-saving measures put in place last year -- including unpaid leave days for state workers and sharp reductions to most counties' transportation funds.

But the governor will likely have to find another $1 billion to squeeze out of the budget.

Even as they welcomed each other back -- and greeted their newest colleague, Republican Del. Charles Jenkins of Frederick County, sworn in yesterday to fill a vacancy -- lawmakers began informal discussions about policy issues that have already emerged this year. Most of those have minimal or no price tags.

Busch said he would push for tougher sex-offender laws after the December abduction and killing of an 11-year-old Eastern Shore girl. A registered child sex offender in both Delaware and Maryland has been indicted in her kidnapping.

Delegates applauded loudly. House Judiciary Chairman Joseph F. Vallario Jr., a Democrat, later said he was expecting "a ton" of bills on that topic.

Following another Day One tradition, lawmakers talked of bi-partisan togetherness.

"All we need to get through this is cooperation," Miller said.

Sen. Allan H. Kittleman, the Senate minority leader from Howard County, said Republicans "want to be part of the solution and not part of the problem."

The governor told the House of Delegates that he enjoys the first day because "it's the lowest ebb of partisanship and the highest ebb of citizenship," as Busch praised Republican House leaders for "the great job they do in giving the opposing view."

But the specter of fall election, which Republicans see as a chance to pick up seats in both chambers, was apparent even during the opening-day prayer in the House of Delegates.

Before bowing his head, Del. LeRoy E. Myers Jr., a Western Maryland Republican, noted ominously, "This will be the last session, for one reason or another, for many of us."

Baltimore Sun reporters Annie Linskey and Childs Walker contributed to this report.