Montgomery County Council members, enjoying a rare truce from the feuds that have divided them for the past two years, yesterday unanimously elected Michael L. Gudis as council president.

Minutes after the election of Gudis, 48, and William E. Hanna Jr., 63, as council vice president, the unanimity dissolved as members split along factional lines to approve a controversial resolution effectively requiring County Executive Charles W. Gilchrist to advertise vacancies on public commissions before making appointments to those boards.

In other action, the council edged closer toward approving a landmark land-use plan for nearly 1,000 undeveloped acres west of Gaithersburg, but delayed a final vote because of proposed state legislation that some officials fear could scuttle a key portion of the plan.

Gudis, leading the council's rush of business before a holiday recess next week, said he was grateful for "the honor of being elected unanimously" to the chairmanship, which pays $38,500 a year. Hanna, the blunt-spoken former mayor of Rockville, echoed Gudis, adding wryly, "At the end of a year, we'll see whether any thank yous are still in order."

The election of Gudis, a wealthy tax accountant who is entering his seventh year on the all-Democratic council, was marked by none of the fireworks that accompanied the election a year ago of Esther P. Gelman as president.

In that election, member Rose Crenca strode out of the room to protest what she later termed the "obscenity" of Gelman's election and member Scott Fosler refused to vote for or against Gelman.

Yesterday, Gelman, referring to the frequent political frays with Crenca, Fosler and Gilchrist during her presidency, said, "Only the County Council lets it all hang out. Only we have our disagreements in public."

Jay S. Bernstein, chairman of the Democratic Central Committee in Montgomery, said Gudis' election should smooth relations among council members and between them and Gilchrist.

"I don't think Michael is as controversial as the other two previous presidents," Bernstein said, referring to Gelman and David L. Scull. "He comes into the presidency without a vendetta . . . whereas Gelman, Scull and Gilchrist were preceived to have a vendatta" against each other.

Gudis, a Brooklyn native and longtime resident of Burtonsville in northeastern Montgomery, has filed few pieces of major local legislation while on the council. He is the architect of a law establishing civil penalties for hate-violence acts and chief sponsor of an annual "sensitivity awareness" program, which was held earlier this week.

In an interview, Gudis said he expects to spend the coming year overseeing the council's work on possible new county landfills, government employe compensation and new school and road construction.

He also stressed that he would attempt to improve the strained relations with Gilchrist. "I will go out of my way to talk with Charlie about problems before they become public issues," Gudis said.