Currently, BT controls a national database of telephone numbers. Other operators, including Mercury, Cellnet and Vodafone, pay for access to the information. One issue Oftel is expected to look at is whether BT should be deprived of its control over the database to ensure fair treatment for its rivals and their customers.
Don Cruickshank, director general of Oftel, said he would also examine the use to which the database information could be put. Directory inquiry services are used extensively by marketing companies, some asking for thousands of numbers a week - a policy which prompted BT to begin charging for the service two years ago.
The company said before charging the cost of the directory inquiry service was adding about pounds 10 a year to telephone bills. It now costs 45p to call to the service, which allows for two number requests. Anyone wanting up to 300 numbers in one week can get them more cost effectively by having their computers linked into the BT database for 6p to 13p a minute.
Those wanting still more numbers can receive them on a computer disc, updated four times a year, for pounds 2,200 a year.
Because there have been worries about people who need emergency access to directory inquiries, BT still offers the service free from telephone kiosks. Free access has also been kept for the old, blind and disabled.