Here are a few more...
Richemont
Internships Listing « ******** – Singapore Internship Programs
Yahoo
Internships Listing « ******** – Singapore Internship Programs
Internships Listing « ******** – Singapore Internship Programs
Sodexo
Internships Listing « ******** – Singapore Internship Programs
Even if the start date doesn't fit your schedule (or has past), you can just write in and ask if they are looking for interns during the period that you are available. Employers appreciate such initiative and it shows your interest in them.