Hong Kong’s largest operator HKT posted a sharp increase in both its net profit and overall revenue last year, as its newly acquired CSL unit and higher ARPU drove mobile revenue up 60 per cent.

The operator’s net profit increased 32 per cent to HKD3.95 billion ($507 million), while EBITDA for 2015 rose 18 per cent to HKD12.1 billion.

The jump in mobile turnover, which included the full 12-month contribution from CSL, helped push overall revenue last year up 20 per cent to HKD34.7 billion. Mobile service revenue expanded 34 per cent to HKD9.2 billion, while handset sales surged 148 per cent to HKD5.1 billion.

Mobile revenue (HKD14.3 billion) accounted for 41 per cent of total revenue for the year ended December 31, compared with 31 per cent in 2014.

HKT said overall mobile growth was negatively impacted by a larger proportion of SIM-only plan customers and a gradual decline in IDD and roaming revenue during the year. Mobile data revenue increased 40 per cent and accounted for 71 per cent of mobile service revenue for the year, while IDD and roaming revenue accounted for 17 per cent of mobile service revenue.

Local data services revenue, comprising broadband network revenue and local data revenue, rose 4 per cent to HKD7 billion, and international telecoms services revenue increased 6 per cent to HKD7.4 billion.

Postpaid ARPU increased 5 per cent to HKD230 ($29.54) at the end of December.

Its mobile subscriber base fell 1 per cent to 4.5 million, with postpaid users dropping 2 per cent to 3.1 million and prepaid connections up 2 per cent to 1.4 million. Broadband subs were steady at 1.57 million.

The cost of sales for the year increased 29 per cent to HKD15.5 billion, which HKT said was in line with the revenue growth during the year.

Capex last year increased 21 per cent to HKD3.05 billion, with mobile accounting for 50 per cent of the total. The operator said after consolidating its mobile cell sites last year, it expects to record “full-year cost synergies” from the network rationalisation in 2016.