Australia's number two telco Optus says it has posted a resilient third-quarter result where net profit rose 4 per cent and operating revenue increased 2 per cent.

Optus, a wholly-owned unit of Singapore Telecommunications, said net profit for the three months to December 31 came in at $A177 million, up from $A169 million in the prior corresponding period.

Operating revenue increased to $A2.42 billion in the quarter, from $A2.38 billion a year ago, SingTel said in a statement.

Optus chief executive Paul O'Sullivan said the company added 182,000 mobile customers in spite of the intensely competitive Australian telecommunications market.

Those new additions comprised 113,000 new postpaid customers and 69,000 prepaid customers, Optus said.