France on Friday froze the assets for six months of companies based in Syria, Lebanon and China after they were linked to an alleged chemical weapons programme in Syria.
The businesses include Sigmatec and the Al Mahrous Group, both based in Damascus; Technolab in Lebanon; and a trading company in Guangzhou in China, according to a list published in the government's official gazette.
Two Syrian nationals will also face asset freezes, as well as a person born in Lebanon in 1977 whose nationality was not given.
The asset freezes were signed by French Finance minister Bruno Le Maire.
In a statement, Le Maire and Foreign Minister Jean-Yves Le Drian said the individuals and businesses were working for the Syrian Scientific Studies and Research Centre, widely known by its French initials CERS.
"The CERS is the main Syrian laboratory in charge of developing and producing unconventional chemical weapons and ballistic launchers," the ministers said.
In January, France sanctioned 25 people and companies based in Syria, and also French, Lebanese and Chinese citizens, over suspicions of fuelling the development of chemical weapons in the war-ravaged country.
The companies targeted included importers and distributors of metals, electronics, logistics and shipping.
Some thirty countries meet in Paris on Friday to put in place mechanisms to better identify and punish those responsible for using nerve agents such as Sarin and chlorine in attacks.
After hundreds of people were killed in chemical attacks near Damascus in August 2013, a landmark deal with Russia was struck to rid Syria of its chemical weapons stash, staving off US air strikes.
Despite the deal, a suspected chlorine and sarin attack in the Syrian town of Douma on April 7 triggered a wave of punitive missile strikes against alleged chemical weapons facilities in Syria by the United States, Britain and France.
The Organisation for the Prohibition of Chemical Weapons is due to soon release a fact-finding report into the suspected Douma attack.
The poisoning of a former Russian double agent and his daughter in Britain last March has also sparked a diplomatic stand-off between Russia and Western powers, which see the hand of Moscow behind the attack.
"After disappearing for nearly 20 years, the return of chemical weapons in the hands of both state and non-state actors in Irak, Syria, Asia or Europe demands the resolute mobilisation of the international community," the French ministers said in their statement.