TOKYO (Reuters) — Toyota Motor Corp. posted a better-than-expected 44 percent rise in quarterly operating profit as robust sales, cost cuts and a soft yen offset higher raw materials prices, and it lifted its full-year forecasts.Toyota has grown rapidly in the United States and Europe with popular fuel-efficient cars such as the Camry sedan and Yaris subcompact, as well as the gasoline/electric hybrid Prius, leaving big local brands struggling to defend market share.

In a move that could further solidify its lead in advanced environmental technology, Toyota also announced an operational and capital tie-up with Japanese truck maker Isuzu Motors Ltd. to jointly develop diesel and other low-emission engines to meet increasingly tighter regulations around the world.

Toyota will buy 100 million shares, or 5.9 percent, of Isuzu from trading houses Mitsubishi Corp. and Itochu Corp. as part of the agreement.

With a market value of $215 billion, Toyota is worth almost as much as the next four top-ranked auto makers — Honda Motor Co., DaimlerChrysler AG, Nissan Motor Co. and BMW AG — combined.

Toyota's sales in the West have more than made up for sluggish demand in Japan, Indonesia and other parts of Asia. Reflecting that trend, Toyota adjusted its regional vehicle sales forecasts, expecting total demand at 8.47 million units this business year, up 20,000 from the previous projection.

Toyota now expects a full-year operating profit of 2.2 trillion yen — about the size of Albania's economy — and net profit of 1.55 trillion yen thanks to a softer-than-expected yen.

Three months ago, it projected record group operating profit of 1.9 trillion yen and net profit of 1.31 trillion yen for the year to end-March. The revision had been expected after Toyota boosted its half-year parent-only projections last month.

Analysts surveyed by Reuters Estimates predict a full-year operating profit of 2.1 trillion yen and a net profit of 1.47 trillion yen.

"These are strong numbers," said Koichi Ogawa, chief portfolio manager at Daiwa SB Investments.

"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."

Japan's top auto maker is set to continue its seamless global product offensive with the big Tundra pickup in the United States — its third crack at the all-American segment — and other models such as the Auris compact in Europe.

Based on current trends, Toyota is on track to overtake General Motors Corp. as the world's top seller of automobiles within a year.

For the July-September second quarter, operating profit totalled 581 billion yen ($4.92 billion), outpacing an average estimate of 527.6 billion yen in a survey of six brokerages by Reuters Estimates.

Net profit jumped 34 percent to 405.7 billion yen, against a market estimate for 372.5 billion yen.

Despite its scale, Toyota's profit growth was among the highest in Japan's healthy auto sector. Honda booked a 19 percent rise in quarterly operating profit, while Nissan, lacking the boost of new product launches, saw profits dip.

Big overseas rivals such as Ford Motor Co., GM and DaimlerChrysler, meanwhile, are faltering under sliding sales in the United States, the world's biggest auto market.

Toyota has outlined plans to win more drivers in the United States through its youth-oriented Scion brand and by beefing up its truck line-up.