Warne was at a book signing the day after his announcement

Leg-spinner Warne has announced that he will quit international cricket at the end of the series.

Ponting said he had been "shocked" by Warne's decision but had used it as a way of reminding the players not to let up in the final two Tests.

"We want to win the next two games. It would be a fitting end for Shane if we did that," he continued.

"With Warney doing what he's done, we can actually use that as some sort of motivation to make sure we send off one of the all-time greats of the game on the right note."

Ponting said Warne had thought "long and hard" before announcing his exit.

"I was a bit shocked, a bit saddened, like everybody else was - not that he'd made the decision but because I've played with him for so long and he's a really good friend of mine and I've learned a lot from him about the game.

"Whenever you lose someone you've been close to for a long period of time, it's sad. But he's obviously made that decision on other things he wants to do in his life, so I didn't at any stage try to talk him out of it," he added.

Warne has so far taken 14 wickets in the series, which Australia lead 3-0, and needs only one more to reach 700 in Tests.

Australian betting agency Centrebet has England's Ian Bell as 6-1 favourite to be Warne's 700th victim, with Andrew Flintoff and Paul Collingwood at 13-2 and Kevin Pietersen 7-1.

The company is predicting Warne will end his Test career with 709 wickets and has Monty Panesar at 3-1 to be the final man he dismisses, but is also offering odds of 33-1 on Warne failing to take a single wicket in Melbourne or Sydney.