Radradra quits Australia's NRL for Toulon
His future has been a contentious topic over the past 18 months, with Parramatta confirming his departure after their 2017 NRL campaign.
Radradra, 24, who is off contract with the Eels at the end of this year, is believed to have signed a deal worth close to Aus$700 000 (US$520 000) a year with Toulon, reports in Australia said.
Parramatta said they would not release him from his 2017 season obligations until November. The European Rugby Union season operates from August through to May.
"In early December 2016 the Parramatta Eels indicated our wish to keep Semi at our club by making a very attractive offer to Semi for the 2017 [upgrade of existing contract], 2018 and 2019 NRL seasons," the club said in a statement.
"The offer from Toulon was substantially higher than our club's offer. We wish Semi well in his Rugby Union venture with Toulon."
While Radradra is set to see out this season with Parramatta, he has a cloud hanging over his immediate future with a court appearance expected next month on domestic violence charges relating to his ex-girlfriend.
Fiji-born Radradra played one Rugby League Test for Australia last year after officials invoked a residency rule for the first time to facilitate his selection.
Radradra, who has scored 60 tries in 68 appearances for Parramatta, previously played four Tests for Fiji from 2013-14.
Agence France-Presse