MANILA - Filipinos may start using at least two mobile phone numbers by 2013, according to a study by global information provider Business Monitor International (BMI).

In its Philippine Telecommunications Report, BMI said the country's cellular penetration rate may rise to 147 percent in 2013, higher than 75.9 percent last year.

"BMI estimates that over the next five years ended 2013, penetration rates will reach 147 percent. Growth during 2009 and 2013 will slow not only due to maturity but as a result of weakened domestic consumption impacted by the Philippine ties with the US and the world recession," BMI said.

The penetration rate is measured by the number of SIM cards relative to the country's population, which has exceeded 90 million as of last year. A penetration rate of over 100 percent means subscribers are using more than one SIM card or mobile phone.

More Filipinos have been subscribing to wireless mobile services for the first three months of the year, but each subscriber has been spending less on voice calls and text messages, based on the financial reports of the country's top two telecoms firms.

Both Philippine Long Distance Telephone Co. (PLDT) and Globe Telecom Inc., respectively the biggest and second-biggest mobile phone service providers, reported continuous growth rates in the number of prepaid users signing up.

What they both noticed, however, is a coordinated and steeper decline in their average revenue per subscriber (ARPU), a key indicator of consumer behavior.

For instance, Globe Prepaid had 14 million SIMs as of end-March from 12.4 million in the same period in 2008. Its gross and net ARPUs, however, declined by 13 percent and 11 percent, respectively.

PLDT's prepaid mobile services from Smart Communications Inc. and mass-market brand Talk 'N Text also shared the same fate, with gross average monthly ARPUs for the first quarter at P272 and P176, respectively. These showed decreases of P20 for Smart and P31 for Talk 'N Text when compared to January to March of last year.