Apple says it has a good reason for blocking the two mobile operators. The Cupertino based tech titan has a preferred partner in Belgium, and that is Mobistar. While that would be all fine and dandy, Mobistar does not offer 4G service. Apple has been known to allow 4G connectivity to operators that are not on its preferred list, but that requires the company to put those carriers through a certification process.
Belgian carrier Base says getting certification from Apple is not easy, calling it an "obstacle course" and accusing Apple of protecting Mobistar in the country. The theory is that Apple is waiting for its preferred partner in the country to start offering 4G service so that Mobistar doesn't lose iPhone business to the other two carriers that do have 4G pipelines.
Belgian economy minister Johan Vande Lanotte offered a proposal that would force smartphone manufacturers to allow their devices to be used on any compatible network, which was passed by the Council of Ministers. And while the threat of getting fined is supposed to motivate Apple into providing equal access to the iPhone in Belgium, it is doubtful that the penalty could be high enough to make much of a dent in Apple's cash reserves.
source: BaseFacts (translated) via ZDNet