Up to 90 percent of all voice call and Internet services from parts of East Asia that were disrupted after Typhoon Morakot damaged undersea cables will resume by the end of Thursday, a senior Chunghwa Telecom official said.

Many Web users in Taiwan, Hong Kong, Singapore and the Philippines experienced slow Internet connections this week as undersea landslides damaged cables connecting them to websites hosted in the United States.

Full repair work on the damaged cables will only be completed in about two months, and Chunghwa is working with other affected telecommunications companies in the region to use alternative routes to restore connectivity.

Chunghwa Telecom, a former state-owned monopoly and Taiwan's largest telecoms company, shares the undersea cables with other operators in East Asia.

We see that most Internet and voice connections should be back to near-normal levels by the end of Thursday, said T.F. Leng, president of Chunghwa's International Business Group.

The typhoon didn't destroy the cables all in one go, which would have led to a sudden outage of services. It slowly destroyed some of the cables, which is why it took a few days before some users were affected.

The cost of repairing the cables will be shared among various telecoms companies, and Chunghwa Telecom's share of the costs should not exceed T$3 million ($91,240), Leng said, declining to name the other companies involved.

The last time Internet users in East Asia experienced an Internet outage as a result of a natural disaster was in 2006, when an earthquake off the coast of Taiwan damaged undersea cables.

(Reporting by Kelvin Soh; Editing by Chris Lewis and Sugita Katyal)