The Number, the UK subsidiary of USA-based INFONXX, has set up the centre to compete in the directory enquiries market which will be opened to competition in December.

The changeover will see the end of the 192 number

In August the company said it would create 200 jobs at the Cardiff Gate Business Park but last week it announced that the numbers of jobs on offer had increased.

Staff are recruiting for posts in in customer services, finance, IT and personnel at the recruitment fair in St David's Hall in Cardiff city centre.

The firm deals with 200 million callers a year in the USA, and employs around 3,000 people worldwide.

The communications watchdog Oftel decided last year to open British Telecom's (BT) near-monopoly of voice-based directory services up to competition.

We think we'll appeal strongly to people wanting to be part of a new team delivering the best customer service in the UK

Robert Pines, chief executive

It hopes the move - which will see the end of the 192 number in August 2003 - will cut the cost of such calls for which BT currently charges 40-60p.

The British enquiries service is used about 600 million times each year and is estimated to be worth �250m annually.

The Number - which will be competing against dozens of firms for customers - is investing �30m in order to establish its new service.

Chief executive Robert Pines said: "We're going to bring to the British public an entirely new experience of directory enquiries.

"That means Cardiff will boast what we believe will be the most advanced call centre in Europe."

Memorable number

Each new service will have a six-figure code which must start with the prefix '118'.

Infonxx has won the rights to what it considers the most memorable new telephone number for the service - the so-called golden number, 118 118.

The new call centre, the company's first in the UK, begins operations from 10 December.

"We think we'll appeal strongly to people wanting to be part of a new team delivering the best customer service in the UK," said Mr Pines.

"Three out of every four management posts in our company are filled through internal promotions, creating real career opportunities."