The 63-Test veteran can't find a home with a British club and is being courted by clubs in Japan and France. His agent, Peter Underhill, said he was having final talks with two Japanese clubs on Tuesday and time was running out for other clubs to sign the British Lions backrower.
"Primarily, we're in negotiations with three Japanese clubs, but I've also had two French clubs ring me," he said. "Colin's performance in Wales' great effort against New Zealand on Sunday didn't exactly harm his cause, and the clubs have been given an ultimatum of this week to put up a deal.
"Everybody knows that we're looking mainly at the Far East, but any offers closer to home will be considered seriously.
"I think it's fair to say we will have agreed terms by the end of this week."
The favourites to sign the Welsh skipper are Japanese side Kobe Steel, who could be willing to pay as much as 200,000 for his services. French side Castres Olympique are also understood to be interested.
If Charvis does go to Japan he will become only the second Welsh player to play in the land of the Rising Sun after former Wales A and Cardiff lock Tony Rees.
Charvis' try against New Zealand on Sunday was his 11th in Tests - equaling Scott Quinnell's record as the leading forward try-scorer in Welsh history.
When a deal with the Neath-Swansea Ospreys broke down, Charvis was leftwithout a club in the buildup to the World Cup, and needed the sponsorship of Cardiff restaurant Zero Zero 32 to cover his insurance costs Down Under.