Antonio Brown's Albany Empire Partners Consulted Attorney, Demand Buyout!

Antonio Brown's ownership "partners" with the Albany Empire say they've been frozen out by the former NFL star, and they have a message for AB ... buy us out, or we're prepared to go to court!

TMZ Sports talked to Charlotte von Schiller and her husband Steve ... who purchased a 5% stake in the organization last year before Brown came on board. Antonio now owns 95% of the franchise.

Unfortunately for the von Schillers, they say things have been absolutely awful since Antonio took over ... and he has even failed to acknowledge they own even the smallest piece of the Empire.

"If he wants to actually own 100% then he needs to buy us out. Otherwise, he only owns 95%, and that's just the facts," Charlotte told us.

The von Schillers tell us they've repeatedly attempted to have civilized conversations with AB about a buyout of their portion of the franchise, but instead, he's essentially told them to get lost, and at times has allegedly berated them on the phone.

"The disregard and disrespect from AB and his group has been incredulous."

In fact, it's gotten so bad, the von Schillers have consulted with an attorney ... and tell us they're ready to go to court if necessary.

But, they hope it doesn't turn into a legal battle ... and would instead like to reach an agreement amicably.

Brown's tenure in Albany, depending on who you ask, has been an unmitigated disaster, with players and coaches quitting midseason over AB's alleged erratic behavior.

Several former players and a coach previously told us Antonio ordered them locked out of their team hotel rooms after complaining about missing paychecks.