The movie star is reportedly working on "Top Gun 3" with the mountain and star crew -- and word is, it's in the early stages at the moment ... with a script being written by 'TG: Maverick' screenwriter Ehren Kruger, and Miles Teller and Glen Powell expected to return.

While we're just hearing about a new 'Top Gun' now, THR reports it's quietly been in development since Fall -- this, of course, on the heels of the huge box office hit from '22.

Now, the larger context here is that just a few days ago ... Tom shook hands with none other than Warner Bros.' chief, David Zaslav, in a big announcement that saw him being brought in as a key producer for several franchise films over at the water tower lot in Burbank.

No word on a dollar-amount figure for Tom's services here -- but he basically agreed to help develop and star in a handful of blockbuster films for WB over the next several years ... and they're even giving him his own office there at their HQ.

On its face, it sounded like he was fleeing Paramount -- a studio he's been tied to forever now ... this after reported rifts in their working relationship of late with the newest regime.

With this 'TG' news, though, it's pretty clear Tom can work with who he pleases and dip his toe into multiple ponds in Hollywood. As many have noted, the WB deal ain't exclusive.