Vodafone shareholders were given a boost today after the mobile phone giant doubled its half-year dividend payout.

The widely-expected increase to 1.91p a share came as chief executive Arun Sarin unveiled a "robust" set of interim figures from the Newbury-based company.

The results were in line with market expectations, although turnover and profits were restrained by the disposal of Vodafone's Japanese fixed-line business. Turnover was £16.8 billion, down on the £16.9 billion seen a year earlier, while underlying profits remained broadly similar at £5.4 billion.Vodafone also expects to double its full-year dividend and will extend a share buy-back programme from £3 billion to £4 billion by the end of March.

Mr Sarin said the strong underlying cash flows of the business, coupled with good growth prospects, had enabled the company to review its dividend policy.

He added that the launch of Vodafone 3G last week had provided customers in 13 markets with a "compelling set of new services". The company said it hoped to have 10 million customers using 3G by the end of March 2006.

Mr Sarin said: "Following the successful launch of 3G services, we are excited about our growth opportunities and ability to leverage global scale and scope advantages."

Vodafone said the UK had been one of the most competitive markets in Europe, but added that turnover in the six months to September 30 still rose 18% to £2.56 billion as it attracted more high value users.

The number of registered customers increased by 4% over the six month period to 14.6 million while the average amount spent per month was £26.60, up on the £25.10 reported a year earlier.

However, Vodafone said margins in the UK fell by three percentage points to 33.3% as it increased investment in the acquisition and retention of customers. As a result, operating profits in the UK fell 11% to £491 million.

Across the group, Vodafone reported bottom-line losses of £1.88 billion, a slight improvement on the £1.99 billion seen a year earlier, as Vodafone continued to take accounting charges in relation to acquisitions made in recent years.

As well as the sale of Japan Telecom, today's figures were impacted by the strength of sterling against the euro and yen.