The 30-year old Argentine centre-back will be added to the Timbers' roster pending the receipt of his International Transfer Certificate and P-1 visa.
Paparatto joins fellow countrymen Diego Valeri and Max Urruti as well as fellow new Argentine signing Gaston Fernandez at JELD-WEN Field.
"Norberto Paparatto brings leadership and experience, two characteristics that further strengthen the club," said Timbers general manager Gavin Wilkinson in a prepared statement.
"He has a desire to play in MLS and Norberto's ambitions as a player are in line with what we want to accomplish as a club. After several scouting trips and speaking to him at length, we are excited to have him on board with the Timbers."
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