Phil Morin with United Steelworkers Local 8914, which represents workers at the Key Lake and McArthur River mines, says workers took down their picket lines Friday morning.
No details on the agreement have been released.
Cameco (TSX:CCO) says the 535 workers at the two mines are to vote on the proposed contract later this month.
Workers have been off the job since late August.
After they voted to strike, Cameco shut down operations at both sites.
"The union and the company have agreed to withdraw the strike and lockout notices issued on August 26, 2014 and preparations are under way to return workers to the sites and safely resume production while continuing to protect the environment," Cameco said in a news release.
"Unionized workers were flown off the sites on August 29, 2014 five hours before a strike deadline. The operations were maintained in a safe shutdown state by salaried Cameco employees and unionized personnel under an essential services agreement with the union."
(CKBI, The Canadian Press)