Saudi Arabia's Mobily reported a 71 per cent tumble in third-quarter net profit on Monday, missing analysts' estimates, after the kingdom's second biggest telecom operator took provisions for bad debts and impairments on its investments.

The firm, also called Etihad Etisalat and 28 per cent owned by the United Arab Emirates' Etisalat, had last Thursday delayed publishing its earnings and suspended trade in its shares as it sought more time to review unspecified "significant matters" in its financial statements.

Mobily made a net profit of SR472 million ($125.8 million) in the three months to Sept. 30, down from SR1.63 billion ($434 million) in the prior-year period, it said in a bourse filing on Monday.

Analysts polled by Reuters had on average forecast Mobily, which competes with the Gulf's biggest operator Saudi Telecom Co and Zain Saudi, would make a quarterly profit of SR1.67 billion ($445 million).

Mobily said the profit drop was because its third-quarter earnings in 2013 were boosted by non-recurring wholesale revenue that was not repeated in the same period of 2014.

Also, depreciation, sales, marketing and general expenses rose year-on-year. These included extra provisions of SR207 million ($55 million) for bad debts, slow-moving inventory and goodwill impairments on its investments. – Reuters