BERLIN, April 23 (Reuters) - Half of German companies are using the government's short-time work facility as most see a decline in revenues due to the coronavirus outbreak, a survey published by the Ifo economic institute on Thursday showed.

Short-time work is a form of state aid that allows employers to switch employees to shorter working hours during an economic downturn to keep them on the payroll. It has been widely used by industry, including Germany's car sector.

Ifo said about 18% of companies surveyed said they wanted to lay off workers or not extend temporary contracts. Ifo said businesses expect restrictions on public life designed to slow the spread of the virus to last about four months.

(Writing by Joseph Nasr Editing by Michelle Martin)