Dear Mr Siew,
I have worked for the company about 1 year 5 months. As stated in the appointment letter, permanent employee is to give a 6 months notice for resignation. My current title is semi-senior executive.
In this regards, appreciate if you may advice whether I shall strictly follow the notice stated or is to according to the employment law, which is 4 weeks notice.
For your information, company will dismiss employee in advance if they managed to find a replacement.
It looks like you have to follow the notice period stated in the appointment letter. If you want an official opinion, give a call to the Labour Department and speak to the officer there.