Fredy Montero, Sporting CP

Portuguese power Sporting Club de Portugal have exercised the club's option to complete the permanent transfer of former Seattle Sounders forward Fredy Montero for an undisclosed fee, the club announced on its website on Thursday.

According to the announcement, Montero, who is currently tied for the Portuguese league lead with 13 goals, has signed a contract through the 2018 season with a release clause of €60 million ($81.4 million).

The Sounders confirmed the transfer Thursday afternoon.

"Fredy has been and will always be a special member of our family," said Sounders FC owner and general manager Adrian Hanauer in a statement.

"Fredy had a wonderful career in Seattle and is continuing that success overseas. Hopefully his quality of play gives him an opportunity to be added to the Colombia World Cup roster. We wish him well with this next chapter of his career."

Montero was loaned to Sporting last July after playing with Colombian power Millonarios during the spring. He joined the Sounders prior to their inaugural MLS season in 2009 and became an instant hit at age 21, scoring 12 goals that season and earning MLS Newcomer of the Year.

He produced 47 goals and 34 assists in regular-season play in four seasons with Seattle, although he was scoreless in 10 career postseason games.

A two-time MLS All-Star, Montero helped the Sounders to three consecutive Lamar Hunt US Open Cup titles from 2009-11, scoring in the 2009 and 2011 championship games.

In Montero's absence, Eddie Johnson, since traded to D.C. United, led the Sounders with nine goals in 2013, while Obafemi Martins led Seattle in goals per 90 minutes, striking eight times in only 20 games.

January reports by Marca in Spain and El País in Colombia indicated that Sporting would pay a transfer fee to the Sounders and MLS of at least €10 million ($13.56 million). For transfers of players who did not come through the draft or a team's youth system, the club receives two-thirds of the transfer fee, and Major League Soccer receives the other third.