* Incident occurs on day of wider protests
* CGT labour union turns against Hollande
* CGT says 90,000 turned out for marches nationwide
(Updates with turnout estimates, poll)
By Pauline Mevel and Brian Love
PARIS, Oct 9 (Reuters) - French riot police fired teargas to disperse protesters outside the Paris auto show on Tuesday as people marched nationwide to denounce hardship and job losses in a country where unemployment is at its highest since 1999 and economic growth has stopped.
The incident came as tens of thousands responded to a call by the CGT labour union, one of the two biggest in France, for the first nationwide protests since Socialist President Francois Hollande took office in May.
Police intervened after around 1,000 protesters including workers from a doomed PSA Peugeot Citroen plant attempted to break through a security cordon around the location of the car show on the edge of Paris, a Reuters reporter at the scene said.
Some protesters pelted the police with eggs and flour during a standoff that lasted about two hours ahead of a central Paris rally that drew upwards of 11,000 people, according to police. The union put that number at 25,000.
France's unemployment rate stands above 10 percent and the number of jobless has topped 3 million for the first time in 13 years.
CGT leader Bernard Thibault, who openly called for a vote to unseat former president Nicolas Sarkozy last May, said nothing was changing under Hollande, who has promised to slash France's public deficit without killing growth or inflicting Greek-style cuts in spending on voters.
"We're deep in crisis because of bad policy responses, quite simply," Thibault told state television channel France 2. "If a majority of employees voted for a change of president it was because they wanted a change of economic and social policy."
Tens of thousands demonstrated in the major cities of Lyon, Toulouse, Bordeaux and the southern port city of Marseille, according to police and union estimates, while protests were also held in smaller cities.
CGT estimates, often twice as high as those of police, put the total nationwide turnout at upwards of 90,000.
"This is clearly a first warning to the government to remind it of the strength in this country," Mireille Chessa, general-secretary of the local CGT union, said in Marseille.
In an Ifop-Paris Match poll published on Tuesday, Hollande's approval rating fell to 41 percent from 47 percent in September. When respondents were asked whether Hollande was in touch with the worries of the French people, only 51 percent agreed, marking a 10 point drop since September.
As marchers hit the streets, lawmakers in the lower house of parliament approved a European pact that commits France, like other euro zone countries, to seek balanced public finances - a pact agreed to in order to stem a debt crisis plaguing the region for more than two years.
The CGT said in a statement that spending cuts being implemented across much of Europe to counter bloated debts and calm financial markets were the "worst of all remedies".
"Workers all across Europe are joining forces to voice their opposition to this policy of austerity and the European treaty," said the CGT, which estimated that half of French wage-earners lives on less than 1,500 euros ($1,900) a month.
Police fired teargas and stun grenades to halt crowds chanting anti-austerity slogans and waving swastika flags in Greece on Tuesday as German Chancellor Angela Merkel made her first visit since the euro crisis erupted three years ago. ($1 = 0.7711 euros)
(Additional reporting by Nicholas Vinocur in Paris, Jean-Francois Rosnoblet in Marseille and Jean Decotte in Toulouse; Writing by Brian Love; Editing by Alison Williams)
Keywords: FRANCE PROTESTS/