Australia's chairman of selectors Rod Marsh has resigned, effective immediately, following Australia's dismal start to the Test summer.

Cricket Australia (CA) confirmed Marsh's departure in a statement on Wednesday afternoon.

No replacement has been named, but CA said it was likely to announce an interim replacement at an extraordinary meeting on Wednesday night.

Marsh, who was appointed chairman of selectors in May 2014, said the decision to leave was his.

"This is my own decision and no-one within Cricket Australia has pressured me or even suggested that I should do this," he said.

"Clearly, though, it is time for some fresh thinking, just as it is for our Test team to welcome some new faces as we build for the future.

"I have always had the best interests of Australian cricket foremost in my heart, and that's why I have made this decision.

"I wish the captain, coach and the team all the best going forward. We will be great again."

Marsh's departure came after Australia's Test side was hammered by an innings and 80 runs by South Africa in Hobart, and by 177 runs in the Perth fixture.

The side was also beaten 3-0 in its recent Test series away to Sri Lanka.

On a dramatic day for Australian cricket, CA boss James Sutherland earlier said it was inevitable changes would be made after the "significant fall from grace", however he had not hinted that Marsh would be leaving.

Cricket Australia Chairman David Peever thanked Marsh for his tenure and described him as an "outstanding person".

"We understand this decision has not come easily for Rod and on behalf of Australian cricket we thank him for his leadership and the integrity and insight he brought to the role throughout his tenure as the National Selector and the lifelong commitment he has given to our sport," Peever said.

Marsh's tenure has included periods of success for Australia.

He oversaw the side which delivered a one day international World Cup victory in 2015. The Test team also enjoyed success, holding onto the number one ranking until its recent form slide.

Marsh, 69, played 96 Tests for Australia as a wicket keeper in the 1970s and 80s, before carving out a career as a cricket administrator.