Newcastle are set to receive a fee similar to that for Aleksandar Mitrovic, who is on the verge of completing a move to Fulham after the two clubs agreed a deal.
This past season, his third with Mainz in Germany's top league, Muto scored eight goals in 27 games.
"He played in the World Cup in a good team".
Newcastle United want to sign Federico Fernandez from Swansea City this summer, according to a report from the Times.
"It means we can bring in another striker and we can be stronger", he said. Since then he has managed a total of 66 Bundesliga appearances, scoring 20 goals and has set up ten more for his team-mates.
Rondon scored seven goals and provided three assists for West Brom last season, finishing as joint top-scorer alongside Jay Rodriguez.
West Bromwich Albion and Newcastle United have been trying to negotiate the deal for weeks, and have reportedly made a breakthrough.