C ALL-BACK technology, which enables businesses to save upto 60 percent on their international telephone calls, is making a good start in the country with three call-back companies already in town in the last two months.

Since Cambodia's telephone rates are the third most expensive in the world, the idea is catching on, with one businessman claiming he already has 20 customers.

Using the technology, the country's own phone system is circumvented by using one of the big American telecom companies.

The formula created by call-back companies is very simple.

Customers will just have to dial an access number in the US, wait for a few rings then hang up. Automatically, the American company calls back the user, who is then connected to the US network and can dial a number to any part of the world at the lowest prices. The only condition is to have a minimum bill of $50 per month.

Thus call-back businesses give their customers access to the cheapest network in the world, the US phone network, which has been liberalized for 12 years now.

Overseas calls to the US will thus cost 68 percent less than with the Cambodian system (down from $4.8 per minute to $2.86 per minute).

A call to Europe will be cut by 40 to 50 percent, one to Canada by 56 percent and one to Australia by 14 percent.

But Thailand and China are notable exceptions, with both costing 10 percent less while using the Cambodian network.

Call-back is a touchy business, because it drives revenues from overseas calls away from the Cambodian government's coffers to US companies.

That is why, even if there is no law here against such practices, call-back companies are eager to run their activities very discreetly.

Nevertheless, when interviewed by the Post , one of these representatives seemed confident: "Call-back companies do not and will never contravene any law.

"How can any government forbid someone from making a call to the US if it allows overseas calls?"

He gave the example of Singapore where 40,000 businesses are already using this technology. Though the Singapore government intended to outlaw this business, it soon realized it was impossible and preferred to cut its own prices by 37 percent.

A Ministry of Posts and Telecommunications (MPTC) official told the Post : "We have not yet considered this problem as it still has no impact on our country."

He added: "Our new off-peak rates, which cut prices by about 20 percent on weekends, already solves part of the problem."

Call-backs between midnight Fridays and midnight Sundays have become less cost effective after the new measure was implemented, as users will just save 32 percent for a call to the US and about 15 on a call to Europe. Customers will even lose 10 percent if they call to Australia and 32 percent while calling to Japan.

But as this service is designed mostly for businesses which work only during the week, it should not hinder call-back activity.