There is no upper limit on the share of foreign equity allowed, except in specific sectors including airline, banking, agriculture and media.
Source:
Section 2.1.2 of Pakistan Investment Policy
https://invest.gov.pk/sites/default/files/inline-files/InvestmentGuide.pdf
Details
As per Pakistan’s Investment Policy 2013, all sectors and activities are open for foreign investment unless specifically prohibited or restricted for reasons of national security and public safety.