Maryland Gov. Martin O'Malley announced his support yesterday for a statewide ban on smoking in bars and restaurants, endorsing legislation that appears to be gaining momentum in the General Assembly.

O'Malley's announcement came a day after the Baltimore City Council passed a bill imposing a smoking ban in public places in the state's largest city. Montgomery, Prince George's, Howard and Talbot counties have prohibitions, and once Baltimore's ban takes effect Jan. 1, nearly half of Maryland residents will live in jurisdictions that restrict lighting up.

"He'll sign it if it reaches his desk," O'Malley spokesman Rick Abbruzzese said of the governor's response to the proposed statewide measure. "He believes the public health data is convincing, and a statewide ban would significantly improve the health of Maryland citizens."

Until yesterday, O'Malley (D) had never explicitly pledged his support for a statewide prohibition, allowing only that he was "willing to consider it" if a bill reached his desk.

Leaders of the state House and Senate, as well as the chairman of the Baltimore legislative delegation, said yesterday that the city's action significantly increases the chances of a statewide law. In past years, opposition from lawmakers in Baltimore, which has myriad corner bars, had been a stumbling block to a statewide ban.

Monday's 9 to 2 vote by the Baltimore council puts "the writing on the wall" for a statewide ban, said Del. Curtis S. Anderson (D-Baltimore), who heads the city delegation. "There's clear momentum."

Still, the chairman of two committees that will consider the legislation cautioned that passage is not certain.

"You can say smoking is banned in half the state, so let's go ahead," said Del. Dereck E. Davis (D-Prince George's), chairman of the House Economic Matters Committee. "But there's also sentiment that this is happening jurisdiction by jurisdiction, so why should the state get involved?"

Sen. Thomas M. Middleton (D-Charles) said yesterday that he is trying to gauge support for the bill in the Senate. "If I find there is not the vote for it, I will not let it out of my committee," Middleton said.

Sixteen states and the District have adopted bans. Some states, including New York and Massachusetts, adopted statewide bans after their largest cities prohibited smoking in public places.

O'Malley, who served seven years as Baltimore mayor before becoming governor last month, had said previously that a statewide ban would be preferable to a patchwork of local bans.

As mayor, O'Malley's opposition to a local ban led supporters of the Baltimore bill to put off voting until he left office, fearing that he would veto the legislation. O'Malley's successor, Mayor Sheila Dixon (D), plans to sign the measure this morning.

Melvin Thompson, lobbyist for the Maryland Restaurant Association, said O'Malley's support for a statewide ban "doesn't change our opposition."

"When you tell people they can't smoke, they will stop drinking in our establishments," Thompson said. "We believe this decision should be made by business owners based on what their customers prefer."

Prospects for a statewide ban have also increased in recent years with the waning influence of the state's tobacco lobby, which occurred as many tobacco farmers converted to other crops.

Advocates for a statewide ban said yesterday that they were within a handful of votes of securing passage in the House committee that will hold a hearing on the bill next week.

Bonita Pennino, a lobbyist for the American Cancer Society, cast the debate in economic terms, saying that Maryland pays hundreds of millions of dollars in health bills for damage from secondhand smoke.

"If the restaurant industry wants to talk about economics, that's our argument, too," Pennino said.

Staff writer Ovetta Wiggins contributed to this report.