Singtel-owned Optus reported a 20 percent jump in net profit to $196 million for the first quarter of its fiscal 2015 year, alongside an 11 percent increase in operating revenue to $2.3 billion.
An extra 38,000 postpaid handset customers and 283,000 4G handset customers contributed to a 5 percent rise in mobile service revenue to $1.21 billion.
Optus' 4G user base now sits at 3.77 million, and the telco now has 4G services available on 3787 sites nationally - close to 90 percent population coverage.
Handset average revenue per user (ARPU) also attributed to positive results, up 9 percent for pre-paid and 1 percent for postpaid customers.
The telco did, however lose 47,000 prepaid handset customers compared to the first quarter of FY14 and 45,000 mobile broadband customers.
Its total number of mobile subscribers now sits at 9.38 million.
Optus had 54,000 NBN broadband customers - thanks to the addition of an extra 18,000 - at the end of the quarter.
It recently completed negotiations on the revised NBN definitive agreements with the federal government.
In May Optus parent Singtel pledged to boost its investment in the telco to S$1.9 billion (A$1.8 billion) over the next year to improve Optus's mobile network and increase its share in the fixed-line market.
The telco is facing the threat of a merged TPG-iiNet, which would leapfrog Optus to become the country's second largest broadband provider behind Telstra.
The merger is subject to ACCC approval.