Lawmakers will vote in a secret ballot, with at least 61 votes required to ensure a candidate become a president and prevent a new general election in the country.
Outgoing President Vladimir Voronin's Communist Party won 60 seats in the assembly in the elections last month. The Communists voted to appoint the outgoing leader parliamentary speaker in Tuesday's vote, which was boycotted by the opposition.
The constitution bans Voronin, who has already served two presidential terms, from serving a third term.
The Plenum of the Moldovan Communist Party's Central Committee has chosen Prime Minister Zinaida Greceanii as its candidate in the forthcoming elections, a source told RIA Novosti.
The parliament set up on Wednesday a special commission for the forthcoming presidential elections. The opposition rejected the offer of three places on the seven-member panel.
The opposition, represented in parliament by the Liberal Party, the Liberal-Democratic Party and the Our Moldova alliance, has 41 parliamentary seats. It has repeatedly stated its refusal to cooperate with the Communists inside or outside of parliament.
The Communists' victory in the April 5 election, which gave the ruling party 49.48% of the vote, sparked protests that turned violent in the capital, Chisinau.
Protests originally led by the opposition spiraled out of control when some 10,000 rioters broke into the presidential residence and parliament. Several hundred protesters and police were injured in the violence.
A number of opposition parties claimed major violations during the voting and said some 400,000 people had been unlawfully registered to vote.
However, election observers from the Organization for Security and Cooperation in Europe gave their overall endorsement to the voting process.
