Mayweather vs. Pacquiao -- MGM Blocking Vegas Hotels from Showing Fight

If you're gonna be in Vegas for the big fight ... and you're not at an MGM property ... you may be S.O.L. -- because MGM honchos are blocking competitors from showing Mayweather vs. Pacquiao ... TMZ Sports has learned.

Here's what we know ... MGM has an exclusivity deal which blocks rival hotels on the Vegas Strip from showing the fight -- and that includes in-room, in bars, in the casino ... anywhere.

Of course, the fight is happening at the MGM Grand on May 2nd -- and clearly, the company is looking to completely corner the local market.

We contacted several non-MGM properties which confirmed the blockage -- and a rep for a major rival hotel told us, "We aren't able to air the fight, that's true. And our guests won't be able to have it in-room either. It's a contract the MGM has. Unfortunately, it blacks out non-MGM properties."

Vegas is expecting hundreds of thousands of people to come in to town for the fight -- and now it seems they'll all have to fight for space at one of the MGM's 14 Vegas properties.

Good luck.