The Asia-Pacific region is leading a worldwide boom in capital expenditure by telecoms service providers, according to new research.

But with growth expected to slow in 2009, analysts from Infonetics Research warn that some companies could be spending more they can afford.

Telcos worldwide are expected to spend $224.6bn on capital expenditure this year, and Asia Pacific will be responsible for 34 per cent of that total, more than any other region.

"For the third year in a row, carrier capital expenditure has increased in all regions of the world, but we expect this investment cycle to plateau in 2009 and decrease in 2010," said Infonetics Research principal analyst Stéphane Téral.

"However, service providers in most regions are operating at a sustainable capex-to-revenue ratio in the 15 per cent range, which should carry the market in these regions through the plateau without much disruption."

The average revenue earned by service providers is also rising worldwide, as carriers launch new services to meet the demands of hundreds of millions of worldwide subscribers, according to Infonetics.

"The Asia Pacific region is worrisome, though, because the average capital intensity rate is a high 21 per cent fuelled by China's rapid growth," said Téral.

"If that rate does not come down, we could be looking at the beginning of another telecom bubble in that region."

Just three firms - China Mobile, China Telecom and Japan's NTT - are expected to account for roughly half of all capital expenditure in the region this year.

Mobile carriers in China will be earning revenues of $123bn by 2012, according to predictions from telecoms analysts at research consultancy Ovum.