By Marie Mannes

STOCKHOLM (Reuters) -Tesla filed a lawsuit on Monday against the Swedish Transport Agency over a workers' strike that has effectively blocked the delivery of license plates for the U.S. auto maker's new vehicles, court documents showed.

Workers at state-owned postal company PostNord joined the strike on Nov. 20 and stopped distributing the license plates to Tesla.

The state-run transport agency turned down Tesla's request to pick up the license plates itself and also declined to send them via distribution channels other than PostNord.

Tesla sued both PostNord and the transport agency in two separate lawsuits, first reported by Swedish business daily Dagens Industri.

IF Metall, Sweden's biggest manufacturing union, is locked in a fight with Tesla to get a collective bargaining agreement for the company's mechanics in Sweden. Metall put the workers on strike on Oct. 27, refusing to service Tesla's cars.

Members of other unions, including dockworkers, electricians and cleaners have since joined in sympathy actions.

The U.S. carmaker has a policy of not signing collective bargaining agreements and says its employees have as good, or better terms, than what the Swedish union is demanding. The union says it is vital to the Swedish labour market model that all companies have collective agreements.

Tesla, in its court filing, called the transport agency's decision not to let it pick up the licence plates "a unique attack on a company operating in Sweden."

It said the refusal to deliver license plates could affect "a large number of consumers who ordered a new car from Tesla".

In 2022, Tesla delivered more than 9,000 electric vehicles to Swedish customers.

The transport agency confirmed to Reuters on Monday that Tesla had filed a lawsuit, believing the agency had not kept its obligations to deliver Tesla's license plates.

"We at the Swedish Transport Agency do not share this view and therefore Tesla has decided to have the issue tested in court, which is their right," an agency spokesperson said.

The spokesperson said it had not seen the lawsuit yet and was unable to provide a more detailed response until the agency had looked into the matter further.

PostNord said it was neutral in the conflict between the unions and Tesla, but that it would need to read the lawsuit before it could comment.

Seko, the union who organised the PostNord workers, told Reuters an easy solution for Tesla was to sign the collective bargaining agreement with IF Metall.

"We see this as a sign that they have not been able to circumvent our sympathy notice," its spokesperson said.

Tesla did not respond to requests for comment.

(Reporting by Marie Mannes and Louise Breusch Rasmussen, editing by Terje Solsvik and Bernadette Baum)