Mobile phone giant Vodafone has promised to create 100 jobs at a new customer centre in Leopardstown, south Dublin, as its Irish subscriber base nears two million.

With new figures showing Vodafone's average revenue per Irish subscriber continuing to rise in the year to the end of March, the company's parent confirmed it was proceeding with a £4.5 billion (€6.54 billion) share buyback at the world's biggest mobile operator by revenue.

The recruitment of 100 new staff for the customer centre will begin immediately and continue for about two years.

Vodafone has about 430,000 shareholders in Ireland as a result of its acquisition in 2001 of Eircell, the former Eircom subsidiary. In theory, a buyback should increase the value of individual shares because it dilutes the overall number of shares in issue

However, Vodafone stock closed nearly 5 per cent down in London last night at 139.5p as concerns about rising competition overshadowed news of the buyback. The group doubled its dividend to 4.07p as earnings before interest, tax, depreciation and amortisation (EBITDA) rose to £13.041 billion from £12.64 billion on sales of £34.13 billion.

While group chief executive Arun Sarin warned of slightly greater competition "all round the world", Vodafone Ireland said its subscriber base rose to 1.952 million at the end of March from 1.864 million a year earlier.

Overall average revenue per user rose to €608 in the year from €582 a year earlier. Contract sale revenues rose to €1,198 from €1,123 while prepaid sales revenues rose to €375 from €361.

The average revenue figure compared with €306 in Britain, €299 in Germany, €359 in Italy, and €414 in Spain. The figure fell 1 per cent in Britain and 3.5 percent in Germany. It was stable in Italy, and rose 10 per cent in Spain.

Vodafone said that monthly minutes of use in Ireland grew 6 per cent during the year and voice consumption remained the highest. More than 640,000 customers had taken up the third-generation "Vodafone live!" product, it said.