Toyota underlined its status as the world's most profitable carmaker yesterday by announcing a 34 per cent rise in quarterly net earnings.

The group also raised its full-year predictions as it rides the benefits of strong global sales, cost cuts and a soft yen offsetting higher raw material costs.

Toyota, set to overtake General Motors as the world's biggest carmaker by volume, has grown rapidly in the US and Europe thanks to popular fuel-efficient cars such as the Camry and Yaris as well as the petrol/electric hybrid Prius, leaving big local brands struggling to defend market share.

In the UK, where it builds the Corolla and the Avensis for European markets at Burnaston, near Derby, the company scored a five per cent sales rise, selling 7,856 units.

That gave it a 5.11 per cent share of the market, up from 4.81 per cent in October 2005. For the July to September

second quarter of its current financial year Toyota posted group net profits of 405.7 billion yen (£1.8 billion), up 33.5 per cent for the same period last year.

Overall sales for the period rose by 17.3 per cent to 5.83 trillion yen (£26 billion).

It raised its profit forecast for the full fiscal year to March 2007 to 1.55 trillion yen (£7 billion) from 1.31 trillion yen (£5.8 billion).

With a market value of £113 billion, Toyota is worth almost as much as the next four top-ranked carmakers - Honda Moto, DaimlerChrysler, Nissan and BMW - combined.

"It looks like Toyota's efforts to overtake GM are going according to plan," Japanese automotive analyst Shiichiro Kobayashi said yesterday.

"Toyota is eating the pie of the Big Three in the US," he added.

Koichi Ogawa of Daiwa SB Investments said: "These are strong numbers. Even next year and beyond we might be able to expect double-digit profit growth.

"It looks like they are the only game in town when it comes to the car business."

Booming sales in the West have more than made up for sluggish demand in Japan, Indonesia and other parts of Asia. Reflecting that trend, the group has upgraded its regional vehicle sales forecasts by 20,000 to 8.47 million units this year.

New products in the pipeline include the Tundra pickup truck for the US market and the Auris small car in Europe.

Despite its scale, Toyota's latest profit spurt is among the highest in Japan's healthy automotive sector. Honda recently reported a 19 per cent rise in quarterly operating profit, while Nissan, short of new products, saw profits dip.

Big overseas rivals such as Ford, GM and DaimlerChrysler, meanwhile, are suffering from a slump in sales in the US, the world's biggest auto market.

Toyota has outlined plans to win more drivers in the US through its youth-oriented Scion brand and by beefing up its truck line-up with the likes of the Tundra.

It hopes to grab even more European buyers with a broader range of diesel-powered vehicles, while at home it is counting on its luxury Lexus brand, a major competitor to Jaguar, to attract customers and improve traditionally low margins.

"We expect profits to improve in all regions in real terms," said senior managing director Takeshi Suzuki.

"All in all, our dependence on North America for profits is steadily decreasing."

Output will expand next year as new factories in Russia, China and Thailand come on stream and boost capacity by a minimum of 560,000 units.

Also yesterday, Toyota announced a move that further improves its lead in advanced environmental technology.

It unveiled an operational and capital tie-up with Japanese truck maker Isuzu Motors to jointly develop diesel and other low-emission engines to meet increasingly tighter regulations around the world. Toyota will buy 100 million shares - 5.9 per cent of Isuzu.