POSTEWART, Northern Ireland - Not so long ago, when telephone companies were monopolies and menus were to be found at restaurants and not on recorded messages ("Press 1 for English. Press 2 for Spanish. Press 3 if you hate this system"), telephone operators were human beings who would offer directory assistance free of charge. Those days have gone the way of the rotary phone and the nickel call.

In the United States, one can still reach directory assistance by dialing either 411 or, for long-distance assistance, an area code followed by 555-1212. Sometimes a human responds. And sometimes a computerized voice comes on the line; you say the name you're searching for, and the same mechanized voice responds with the number. It costs about a dollar per inquiry.

In the United Kingdom, one used to be able to request a phone number by dialing 192 for residences or businesses, or 153 for long-distance information. But government regulators here concluded that if they broke up the British Telecommucations, or BT, monopoly on directory assistance, consumer prices would drop and service improve.

Thus, last weekend, the two old information numbers were scrapped. Now customers find themselves choosing from up to 20 competing numbers - each having the same 118 prefix but followed by three more numbers.

The new system is confusing and complicated and, as it turns out, even more expensive than the old.

All of Britain's phone companies now offer their own directory assistance services, as do a number of companies that aren't even in the telecommunications business. Among them is British Gas (118-511) - which may be what the new system will give many of its customers. British Gas information calls average a little more than US 50 cents a minute, which means you pay for the time it takes the operator to find the number for you. There is also a gay and lesbian information service (118-453), which is the most expensive of the new options, at about 90 cents a minute. My favorite is Welsh information: Ymhotiadau rhifau ffon BT Y DU (118-404). (NOTE TO EDITORS: PLEASE ADD A CIRCUMFLEX OVER THE O IN FFON.)

Under the old BT system, 60 cents would have gotten a caller up to two numbers, and there was no time charge for the service. Today the pricing system is a mess; some firms charge a flat fee, while others charge by the minute or even second. Have fun with your comparison-shopping. The Sunday Times of London conducted a survey of the new companies and concluded that "it is almost impossible for customers to identify the cheapest service as they still do not know how long the call will take."

And while several of the new companies offer to connect the caller with the number requested, the Times survey found that not one operator indicated that the connection charge could be up to 10 times the cost of a direct-dial call. Continued...