Workers from a wide range of sectors are protesting against pension reforms.
More than 800,000 people took to the streets on Thursday, with violent clashes reported in a number of cities.
Other unions are expected to decide on Friday about their further strike plans, Reuters reports.
Widespread rail cancellations and disruption to flights are expected on Friday with only a fraction of the capital's transport system working.
Paris's bus and metro operator have said their walkout will last until Monday at least.
Many French workers are angry about President Emmanuel Macron's plan to introduce a universal points-based pension scheme.
It would replace France's current system which has 42 different pension schemes across its private and public sectors with variations in retirement age and benefits.