Where to improve business Swedish? (Stockholm)

Dear all,

I have been living in Sweden for almost 10 years, but the entire time I have been studying and working in English only... Only took the basic Swedish classes at the university. Thus my Swedish is quite far from fluent. I fully understand Swedish and can have day-to-day conversations with no problems, but as I never had a chance to properly practice the language I can not do business/negotiations in Swedish and my grammar is far from perfect - thus can not write proper business emails=(

Would very much appreciate if you could suggest which road I should take in improving my Swedish - University courses, or some associations? If you can recommend a particular course - that would be great.

Thank you very much and have an amazing weekend,
Jaros