VILNIUS, Lithuania -- An unexpectedly high turnout in Lithuania's first parliamentary election as an independent nation appeared likely Sunday night to guarantee that fewer than 40 of the 141 seats open in the new parliament would require a second round of voting.


Final election results, as well as an answer to a referendum on the country's proposed constitution, were not expected until Monday morning.


"We're obviously very pleased", said Juozas Tumelis, chairman of the council for the nationalist Sajudis movement, whose leader is Parliamentary Chairman Vytautas Landsbergis.


"We expect that most races will be decided tonight".


By early evening, 58 percent of the electorate had cast their ballots, according to the Lithuanian Chief Electoral Committee. Tumelis predicted that, by the time the polls closed at 10 P. M. , the turnout would reach 70 percent.


A high turnout is needed to approve the new constitution that requires an absolute 50 percent majority to pass.


The elections were held to fill the new 141-seat parliament, the Seimas, which will replace the old parliament that has ruled the country since 1990.


At a polling station located in the Music Academy of Lithuania, where Landsbergis once worked as a professor, volunteers handed voters three ballots: The first to select one of 17 parties, the second to select the candidate from their district and the third to vote yes or no on the proposed constitution.


Lithuania has managed to avoid the charges of discrimination against Russian-speakers that marred the recent presidential election in nearby Estonia. Besides having a Russian population of less than 10 percent, Lithuania has only loosely enforced its language requirement for citizenship.


The election is an important test for the increasingly fragile Landsbergis-led coalition government that has ruled Lithuania since independence in August, 1991. Dissatisfaction over a severe energy crisis, inflation running at 25 percent in August alone and the government's failure to introduce a fully convertible currency have led to sharp criticism of Landsbergis.


In September, an opinion poll conducted by Baltic Surveys, showed that only 18 percent of Lithuanians believed that the government was acting in the people's best interests.


Meanwhile, the referendum on the constitution is considered crucial for advocates of rapid reform. It would create the new post of president, to be elected within four months. Reformers see the post, which has the power to dissolve local governments, as a launching point for a campaign against "saboteurs" who they say are impeding reform.


The country is presently being led by its fourth prime minister since January, 1991, an indication of its paralysis.


The last prime minister, Gediminas Vagnorius, was sacked after a group of parliamentarians defected from Landsbergi's coalition and sided with the Leftists, led by Algirdas Brazauskas, the former Lithuanian Communist Party secretary.


With the appointment of Prime Minister Aleksandros Abisala, enough Centrists returned to the Landsbergis camp to once again rule the nation, as well as agree to a final draft of the constitution.