FRANKFURT, Germany (AP) _ German automaker Audi AG said Tuesday consumer willingness to pay for luxury models helped boost its net profit by more than a third in the first half of the year.

The Ingolstadt-based company, part of Volkswagen AG, said it earned 407 million euros (US$519.6 million) in the January-June period, up 36 per cent from the 300 million euros it posted a year earlier.

Revenue was up 17 per cent to 15.4 billion euros ($19.6 billion) from 13.2 billion euros last year. Audi did not release second-quarter figures.

Worldwide, sales were up 9.8 per cent with 463,494 cars sold in the first six months of the year, compared with 421,965 in the same period last year.

Rupert Stadler, an Audi board member who oversees finance, pointed to consumers' willingness to spend more money on higher-priced vehicles.

``The substantial growth in earnings is due to the fact that we are selling significantly more vehicles with more exclusive specifications in vehicle segments higher up the range,'' he said.

Chief executive Martin Winterkorn said the company had made ``good progress along our course of profitable growth.''

``Our aim is to sell 50,000 vehicles more in 2006 than we did in the previous year,'' he said.

Audi's models include the A3, A4, A6 and A8, along with the TT Roadster and an all-wheel drive wagon, the Quattro.