Somerset have signed three overseas players for the 2006 season.
White launches an appeal playing for Queensland
The county had held talks with South Africa captain Graeme Smith and Australia skipper Ricky Ponting but have been forced to look elsewhere.
South African left-arm seamer Charl Willoughby joins as a Kolpak player, allowing Australian spinners Cameron White and Daniel Cullen places as well.
"The two young Australians are exciting possibilities," director of cricket Brian Rose told BBC Radio Bristol.
"People like Shane Warne and Ricky Ponting are already tipping Cullen for the Test team within two years."
Cullen, 21, has played 17 first-class matches in Australia and taken 66 wickets, taking five in an innings three times.
White, a year older than his compatriot, has already played five one-day internationals for Australia, taking just the solitary wicket with his leg-spinners.
A useful batsman in domestic cricket, he averages 29.27 in first-class matches and has nine fifties and a century to his name.
Willoughby, now 31, has previously played in England for minor counties side Berkshire and spent last season with Leicestershire, where he took 33 championship wickets at a cost of 39, with a best of 4-92.
He made his international debut in 2000 but played the last of his three one-day internationals in 2003 and the last of his two Tests in the same year.
The South African has signed a three-year contracct and Rose said: "He is particularly effective in one-day cricket, but also has a
decent first-class record.
"He will be able to work with Rob Woodman to aid his