India have dropped one place to third in the updated one-day rankings despite winning the World Cup earlier this year, cricket's governing body said on Monday.
The International Cricket Council's annual update, which reflects recent form, removed results from matches played before August 2009 without giving extra weighting to World Cup wins.
Mahendra Singh Dhoni's men won the one-day tournament in April, India's second World Cup success after Kapil Dev's team won in 1983.
Over the past 12 months, India had a worse win-loss ratio than defeated World Cup finalists Sri Lanka and quarter-finalists Australia and South Africa, the ICC said.
Australia continue to lead the rankings with 130 rating points, way ahead of Sri Lanka (118), India (117), South Africa (116), England (106) and Pakistan (100).
Australia captain Michael Clarke, due to play a one-day and Test series in Sri Lanka this month, said his side was determined to maintain its lead at the top of the table.
"This Australian side is extremely proud to be ranked the number one one-day side in the world," Clarke was quoted as saying in the ICC release.
"Being knocked out of the World Cup at the quarter-final stage was very disappointing and our group has already started its planning to reclaim the title on our home shores."
Australia and New Zealand will co-host the next World Cup in 2015.
The two World Cup finalists, India and Sri Lanka, will join Australia in a one-day series Down Under in January.
India will also give up their top spot in the Test rankings if they lose the ongoing four-match series against England by two Tests or more.
ICC one-day rankings (previous rating points in brackets):
1. Australia 130 ratings points (129)
2. Sri Lanka 118 (116)
3. India 117 (119)
4. South Africa 116 (116)
5. England 106 (108)
6. Pakistan 100 (100)
7. New Zealand 90 (94)
8. West Indies 78 (76)
9. Bangladesh 70 (67)
10. Ireland 42 (41)
11. Zimbabwe 38 (37)
12. The Netherlands 5 (10)