The following portal may be of interest to students looking for internships at schools abroad:
www.erasmusinschool.com/
Note that many of the opportunities involve teaching English (or German) in non-English speaking countries such as Spain or China – these will obviously not count towards the compulsory stay abroad, but could be an interesting way to extend your teaching experience.
There are also some jobs available in countries with English as the official language, such as Ghana or India – read through the different advertisements (www.erasmusinschool.com/findschools#) carefully!
Please direct any further enquiries to the website (www.erasmusinschool.com/faqen).