The Belfast boxer contacted Irish-Boxing.com this afternoon to confirm the split.
27-year-old McCarthy signed with MTK last August, moving from long-time manager Pat Magee, but has only fought twice since.
The Lenadoon big man defeated Peter Hegyes and Blaise Mendouo in quick succession but has been out of the ring since last November despite there being three major fight cards in his home city.
This year McCarthy has spent time out in Kazakhstan sparring with former WBA light heavyweight champion and current cruiserweight ‘regular’ beltholder Beibut Shumenov and in Manchester with recent heavyweight world title challenger Hughie Fury but has seen had no action in a competitive ring.
During this time McCarthy has witnessed plenty of moves on the domestic scene with Matty Askin, who he was defeated by in a final eliminator in 2016, defending his British title versus Stephen Simmons and setting up a fight with Olympian Lawrence Okolie next weekend at Wembley.
Matchroom’s Okolie has rattled off some good wins himself, outpointing Isaac Chamberlain before destroying McCarthy rival Luke Watkins to win the Commonwealth title. Okolie’s vanquished opponents are set to meet in Novmeber while that month will also see the vacated Commonwealth belt contested by Wadi Camacho and Arfan Iqbal.
Having been calling for such fights, McCarthy will be keen to get back in the mix as soon as possible.
Leaving MTK, the former elite amateur international is currently unattached.
‘The Mac Attack’ McCarthy is the sixth Irish fighter to leave the large management outfit after Ciaran McVarnock, Shortty Carroll, Craig O’Brien, Jake Hanney, and Sean Creagh (who later re-joined).