EDIT, removed old answer
In response to DJClayworth, yes business visas are different from work visas. Work visas allow you to work in the country as part of a business or on your own. Business visas are required if you're travelling to visit a business in the country for work.
However, my old answer was wrong. Since Sweden has a separate business visas that would be required for business visits, training, and conferences. Not all European countries draw this distinction (the base visa is still a Schengen C-visa).
Since the company is paying the expenses, and you'll need to explain this on the visa, I think you do need a business visa. Otherwise you stand a chance of being refused when you explain how you're paying for your stay.
However, definitely check with the inviting company, they should know or at least be able to find out more easily. And e-mail the Embassy, I've had great results e-mailing embassies -- I almost never call because they rarely answer their phones.