Develop Your English recommends the Cambridge University, English Language Examinations. These exams can be taken in Bern or Thun.
First Certificate in English
Cambridge English: First, also known as First Certificate in English (FCE), is an exam for people who need to prove they can use everyday written and spoken English at an upper-intermediate level for work or study purposes. This is the exam that many employers want from their employees in Switzerland to show that they have a good understanding of English.
Certificate in Advanced English
Cambridge English: Advanced, also known as Certificate in Advanced English (CAE) is the leading English exam for professional and academic success. This is the exam to show you have more than just a good understanding of English.
Certificate of Proficiency in English
Cambridge English: Proficiency, also known as Certificate of Proficiency in English (CPE), is the most advanced Cambridge exam, for learners who have achieved an extremely high level of skill in the English language. This is the exam to show that your knowledge of English is not much different from an educated native English speaker.