The Spanish champions are believed to have identified the Argentina international as a leading transfer target ahead of the opening of this summer's transfer window.
Marotta, however, has said that Inter will only consider selling the South American if he asks to leave, and the Inter CEO for sport is confident that the Serie A giants can keep hold of the centre-forward.
"Lautaro Martinez to Barca? He's focused only on Inter, he's a young talent and Inter have nothing to envy to Barca or other clubs. We can sell players only if they ask to leave," Marotta told Sky Sport.
Martinez has been in impressive form for Antonio Conte's side this season, scoring 16 times in 28 appearances in all competitions.
The 22-year-old, who has also been linked with Manchester United and Real Madrid, is thought to have a £94m release clause in his current deal at San Siro. body check tags ::