Libya's parliament spokesman said the chamber had selected a new prime minister on Thursday after one of the two candidates withdrew.
A video showed parliament members raising their hands when asked to support Fathi Bashagha, a former interior minister, to head a new interim government, but it was not clear if any formal vote had actually taken place.
The parliament is seeking to take control of Libya's political future after the collapse of an election that was planned for December, saying Abdul Hamid Dbeibah's interim government is no longer valid and pushing any new election back until next year.
Dbeibah said on Tuesday he would cede power only to an elected government and rejected the parliament's moves to replace him.
The UN Libya adviser and Western countries have said Dbeibah's Government of National Unity remains valid and have urged the parliament to focus instead on bringing elections forward.