I'm not sure that you do need a work permit as such, as I understand it you need to get a residence permit if you are going to stay longer than 6 months. Provided you are going to be employed for over 12 months, you get granted a five year residence permit and for employment up to 12 months a residence permit is granted for the length of the employment.
These links might be of use:
http://europa.eu.int/eur-lex/pri/en/...en00060063.pdf
http://www.foreigners.ch/news_info/index_e.asp?lang=e
http://www.eda.admin.ch/london_emb/e...blatt-engl.pdf
Entry formalities
The following are required in order to take up employment in Switzerland:
- valid passport;
- assurance of a residence permit in order to take up employment (which must be obtained from the appropriate authority - Aliens Police or employment office - by the employer); in the case of persons subject to a visa requirement: a visa to take up employment, issued by the appropriate Swiss embassy or consulate for the foreign national’s place of residence;
- employment contract.
Entry into Switzerland for the purpose of taking up paid employment is not permitted without these papers.