French business confidence plunged to a more than two-year low in December after violent anti-government protests as the economy closes the year on a rough note, official data showed. 

The confidence slump implies the economy has slowed since growth peaked this year in the third quarter at 0.3%, which today's data showed was weaker than previously thought. 

The INSEE statistics agency said its business confidence index fell to 102 points in December from 105 last month - the lowest level since November 2016. 

Confidence in the retail sector suffered particularly badly after Paris saw the worst unrest in decades from "yellow vest" demonstrators during crucial, pre-Christmas shopping days this month. 

The index for the retail sector fell to 100 from 107, its lowest since January 2015. 

Many businesses in central Paris have had to board up on Saturdays after some had windows broken during the rampaging through some of the French capital's poshest neighbourhoods. 

Parisian department store Printemps has seen sales at its flagship store slump around 10% in December, its chief executive Pierre Pellarey told French radio. 

The protests have also hit hotels in the world's top tourist destination, costing the industry in Paris €18m in lost revenue from cancellations. 

Earlier this week, INSEE forecast the economy likely slowed to 0.2% growth in the final quarter due in part to the protests over fuel tax hikes squeezing household budgets. 

Already in the third quarter, the economy grew only 0.3% from the previous three months, INSEE said today, revising down from a previous estimate of 0.4%. 

After tax rises and transport strikes weighed on activity in the first half of 2018, the economy is on course for soft full year growth, which INSEE has forecast at 1.5%. 

The third quarter data lent some credence to protesters' claims their purchasing power is squeezed by high taxes. 

The government offered concessions this month aimed at boosting the poor's income. 

INSEE said households' real disposable income growth slowed to 0.4% in the third quarter from 0.8% in the previous three months as wage growth slowed and the tax burden rose. 

But consumer spending grew 0.4% in the quarter after pulling back slightly in the previous period as households saved marginally less. 

The savings rate eased to 14.4% from 14.5%.