Under the Employment Act, an employees only entitled to annual leave after completing 12 months service. If the company wants to give annual leave after 3 months confirmation, it's up to the company to do so. There's nothing wrong about it.
KL Siew has put up a sister site by the name of mylabourlaw.net, which is in effect a more user-friendly version of the present popular pesaraonline.net. The site is in the process of being fine-tuned but it is fully functional. You are invited to visit the website at http://www.mylabourlaw.net and give your views or suggestions. Queries can be posted and be responded from there as usual.