Yes, if unions exist at the company (which they did at Klarna), a company is required by law to negotiate with ALL employee organisations present at the company. This is one of the reasons large companies adopt kollektivavtal, it allows them to only have to negotiate with one union for employment changes.

Source (Swedish law): https://lagen.nu/1976:580#P13S2

Google translated:

> If the employer is not bound by any collective agreement at all, the employer is obliged to negotiate in accordance with § 11 with all relevant employee organizations in matters relating to dismissal due to a lack of work [...]

I'm no expert but how I under stand it is the company can offer x months of pay if you leave by your self. This does not need to be negotiated with the union. If this makes enough people leave, there will be no negotiation. If however they want more to leave they have to negotiate with the Union that the workers are connected to, it does not matter if the company have a contract with them or not.

Also, they have to give six months notice to the unemployment agency if they plan to fire more than 100 people.