Pakistan's telecoms regulator has given the go-ahead for Pakistan Telecommunication Company Limited (PTCL) to acquire Telenor in Pakistan.

It comes two years after the deal was first announced, when Telenor agreed to sell the unit for $490 million.

The transaction is set to make PTCL the second-largest mobile operator in the country for subscribers.

It's expected to close the deal next year, two years after PTCL had expected to close the deal. The acquisition only received approval from the Competition Commission of Pakistan in early October.

Following this, the Pakistan Telecommunication Authority (PTA) has also given its blessing to the deal after carrying out a review.

"With this NOC [No Objection Certificate], PTCL may proceed with the acquisition, subject to completion of all legal and commercial formalities," the PTA said. "Both companies must ensure continuity and quality of services and uphold all license obligations throughout the transition."

Telenor first launched in Pakistan 18 years ago, and has built a subscriber base of more than 42 million.

The acquisition will see PTCL add those customers with its own subscriber base (via its Ufone brand) of just over 27 million to create Pakistan's second-biggest telco.

Telenor had been considering a merger deal in the country, but decided to sell the unit entirely. Telenor has previously completed merger deals in Malaysia and Thailand.

In April of last year, PTCL secured $400m in debt financing for the acquisition.