Total is restarting operations at the Grandpuits, Gonfreville and Feyzin refineries, all three of which have been offline since late May as union workers walked out in protest of a new labour law.
But the Donges refinery on France's western coast was still being blocked by about 30 members from the CGT union.
France is a net gasoline exporter and the resumption of refining operations there was set to increase supplies in the European market amid weak demand, traders said.
News of the French refinery restarts and heavy imports alsow weighed US gasoline refining margins with the RBOB crack hitting a 4 week low of $17.46 a barrel.
Traders said around 800,000 tonnes of gasoline are set to arrive in the US in June from Europe.
Higher global refining capacity in the summer months is expected to put new pressure on margins, particulalry diesel cracks, Morgan Stanley said.
Around 2.7 million barrels per day of refining capacity is set to return from maintenance globally from May to June, according to Morgan Stanley. An additional 2 million bpd will return in July.
GASOLINE
There were no eurobob gasoline trades during the Platts afternoon trading window.
About 4,000 tonnes of benchmark eurbob barges traded throughout the day at $518-$521 a tonne fob Amsterdam-Rotterdam-Antwerp, compared with $522 a tonne on Friday. Cargill and Litasco sold to Shell.
Glencore sold to Total a premium unleaded gasoline barge at $520 a tonne fob ARA, compared with bid and offer discussions at $518-$521 a tonne on Friday.
The July swap stood at $517 a tonne at the close, down slightly from $519.50 a tonne. * Gasoline barge refining margins fell to $12.38 a barrel from $13.12 a barrel.
Brent crude oil futures were up 90 cents at $50.54 a barrel at 1538 GMT.
US July RBOB gasoline was down 0.49 percent at $1.5996 a gallon.
The US gasoline crack was trading at $17.50 a barrel, down from $18.95 a barrel on Friday.
No cargoes traded. Glencore bid at $426 a tonne for delivery into northwest Europe on June 16-20.