He replaces the former Communist Vitold Fokin, who resigned on Wednesday after criticism that he was dragging his feet on market reforms. President Leonid Kravchuk ordered ministers sacked en masse by parliament on Thursday to retain their posts for up to 20 days pending the appointment of a new government.
Mr Simonenko's temporary appointment puts him in line as a possible permanent prime minister. Another potential candidate is Leonid Kruchina, manager of a military enterprise in Dnepropetrovsk. Mr Simonenko, 52, a former senior Communist Party official and mayor of Odessa, replaced the Western-oriented radical economist Vladimir Lanovoy who was sacked by Mr Kravchuk in July.
He told parliament on Wednesday: 'We should slightly support the old (economic) structures and at the same time launch the construction of a new house.'