Rossi insists he must have a much-improved bike for next season

He was second fastest in qualifying for Sunday's Australian MotoGP, with Honda's Dani Pedrosa on pole and 2007 title-winner Casey Stoner in third.

Five-time champion Rossi said: "Yamaha have to show me something now, make a good bike for 2008. If nothing changes, I can look for another opportunity."

Rossi's contract with Yamaha runs out after the 2008 season.

The 28-year-old won the MotoGP crown every year from 2001 to 2005, three times with Honda and twice with Yamaha.

He added: "I gave a lot of success to Yamaha in these past years, now I wait for something from them.

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"If we want to win the title again then we need the people in Japan to put in more effort. We need to be more aggressive and brave in the development decisions."

Saturday's qualifying session at Phillip Island saw Pedrosa clock one min 29.201 sec, 0.218 faster than Rossi.

Home hero Stoner, who won the title two weeks ago in Japan, was 0.615 off the pace, third-fastest on his Ducati.

Pedrosa's time was two-tenths of a second slower than the lap record set last year by American Nicky Hayden.

Hayden, who claimed the world title in 2006, will start from fourth on his Honda.

It was the third pole of the season for Pedrosa, currently third in the standings behind Stoner and Rossi.

Australian MotoGP qualfying:
1. Dani Pedrosa (Spa) Honda 1min 29.201sec
2. Valentino Rossi (Ita) Yamaha +0.218
3. Casey Stoner (Aus) Ducati +0.615
4. Nicky Hayden (US) Honda +0.731
5. Loris Capirossi (Ita) Ducati +0.889
6. Randy De Puniet (Fra) Kawasaki +0.909
7. Alex Barros (Bra) Ducati +1.124
8. Shinya Nakano (Jap) Honda +1.411
9. Slyvain Guintoli (Fra) Yamaha +1.420
10. Anthony West (Aus) Kawasaki +1.448