European mobile phone operator Orange has seen its operating profits triple to 819m euros ($728m, �501m) in the first half of the year.

And its customer base has swelled by 52%, driven by growing popularity in the UK as it gains ground on its arch-rivals Vodafone and BT Cellnet.

But despite the healthy gains, the firm still racked up a loss of 500m euros, compared to 582m euros in the same period a year earlier.

And net debt at the end of June stood at just over six billion euros.

Orange is the leading mobile operator in France and number two in the UK.

It was bought by France Telecom from Vodafone last year and now accounts for one third of the French firm's overall income.

International expansion

"Orange is showing rapid growth, improved margins and a very powerful balance sheet," said Orange chief financial officer Graham Howe.

Mr Howe noted the firm was on track to meet the profit targets that it set itself at its flotation in April.

And initial plans to generate one quarter of the group's revenues from non-voice services such as text messaging and data now seem conservative, he added.

The company also has ambitious plans to increase its international presence, aiming to expand into 50 countries by 2005.

Sneak preview

Investors got a sneak preview of Orange's results when France Telecom accidentally leaked a memo to analysts last week.

Following a computer error at the press office, analysts were informed that profits excluding the costs of interest payments, tax, depreciation and amortisation (Ebitda) had risen 102% to 1.63bn euros, far exceeding expectations.

Even though the company asked investors to ignore the information, shares in Orange rose 8% on the morning after the error.

On Thursday, Orange shares joined the slump in European stocks, standing 2.0% lower at 7.36 euros in lunchtime trade.

The shares were floated at a price of 10 euros, and hit a high of 12 euros in April.