Not really. As someone who saw the union reps agree to give up my pension (read deferred compensation) I am very familiar with pensions, pension fundings and pension terminations. I am familiar with how pensions are funded and what happens after they are either terminated or frozen in the US at least. Maybe and more likely from the heat I am taking, the pension system in Norway is markedly different.
If my posts offended, my apology. And again, maybe everyone in Norway understands pensions. That is not the case in the US. Many seem to think it is some a kind gesture by the company when in fact, the pensioner has paid for and invested in the deferred compensation. You accrue x benefits based on your time with the company and YOUR earnings, not someone else's. And although the pension was negotiated by collective bargaining, the union puts nothing in the pot toward the pension.
In the US, companies took the deferred compensation and invested it or bought annuities which then made payments to pensioners. It is not now and never was some gift for being a good, long term employee.
As for laws and as for what is negotiated, you will find (If Norway is anything like the US) that a mere stroke of the pen will give and take away. In the US, after 9-11 many companies used the 'force majeure' clause to essentially gut the contracts. And when the employees challenged the company for enacting the clause, the courts said, "Nope.. they can do that." And the company walked away from contract after contract.