As of my knowledge cutoff in September 2021, here are some of the top construction companies in Pakistan:

1. National Engineering Services Pakistan (NESPAK)
2. Descon Engineering Limited
3. Habib Construction Services (HCS)
4. FWO (Frontier Works Organization)
5.  top construction companies in Pakistan:
6. Nishat Group
7. Lahore Development Authority (LDA)
8. Paragon Constructors (Pvt) Limited
9. Pakistan Construction & Quarry (PCQ) Magazine
10. Bahria Town
11. 

Please note that this list is not exhaustive and the rankings may have changed since my last update. It is always advisable to conduct further research and check for more recent information to get an up-to-date list of the top construction companies in Pakistan.