Rondon will join Newcastle on loan, with Dwight Gayle making the switch to West Brom.
Both players are said to want to have permanent clauses put into their loans, which could be activated should either perform well.
Newcastle boss Rafael Benitez has been chasing Rondon for some time, and appears to have finally got his man, after using Gayle as a makeweight in the deal.
Gayle had previously stated that he wanted to stay at Newcastle, but his first-team chances for Rafael Benitez’s side were always set to be limited.
Newcastle have already brought in one striker this summer, with Yoshinori Muto signing up for the season.
Rondon scored seven goals for the Baggies last term, but was unable to stop them from being relegated.