Australian telecommunications carrier Optus has recorded its strongest growth in five years with its net profit in the three months to June showing steep increase.

The SingTel subsidiary posted $170 million net profit for the June quarter, a jump of 22.4 per cent on the corresponding period in 2009.

Operating revenue edged up 2.6 per cent to $2.26 billion.

According to SingTel, Optus experienced the strongest quarterly EBITDA (earnings before interest tax depreciation and amortisation) expansion in five years and this was mainly led by strong mobile growth and prudent cost management.

The telco's operational EBITDA climbed 9.7 per cent to $553 million.

Overall, the SingTel group's net and underlying profit declined 0.2 per cent, at $S943 million ($A773.2 million), while operating revenue increased 11.5 per cent on the previous equivalent period, at $S4.29 billion ($A3.51 billion)

Optus posted seven consecutive quarters of double-digit mobile service revenue growth, SingTel said.

"In (Optus) mobile, service revenue rose 11 per cent year-on-year, matched by strong EBITDA growth of 11 per cent."

"Optus' continued investment in the mobile network has delivered significant improvement in coverage and performance over the last 12 months."

During the 2010 FIFA World Cup, Optus delivered over 350,000 live streams of the FIFA World Cup matches to customers.

"The Singapore and Australia businesses turned in strong performances, especially in mobile with both reporting double-digit revenue growth," SingTel group chief executive Chua Sock Koong said.

SingTel predict operating revenue and EBITDA at its Australian arm to grow at mid single-digit levels for the year ending March 31, 2011. Capital expenditure is forecast to be about $1.2 billion.