Johns Lyng Group shares have plunged over 14% to $2.40 after news that the building services company will be removed from the ASX 200 index.
The firm, which specialises in building and restoration services, including post-disaster reconstruction, is among seven companies set to exit the index before trading starts on March 24.
Casino operator Star Entertainment will also be removed under changes announced by S&P Dow Jones Indices following its March quarterly review.