@Shakoor. This is a very standard tactic employed by PML govt which allows them to push through mega projects on a fast track basis. Splitting a big project into smaller ones has many advantages. First, at the approval stage, the higher the project cost the higher the approval forum, greater technicalities and consequent delays. By splitting a project, approvals can be obtained from a much lower forum than ECC.
Secondly, splitting allows faster implementation. Each contractor is responsible for a small section of the project in which he has to show his performance, so work gets done faster. Recent examples include the Islamabad Metro project, Lahore ring road etc.
Lastly, and maybe more importantly, this also allows the government to provide an "opportunity" to more contractors rather than dishing it all out to one. However if past record is anything to go by, this should result in faster progress.