By TMZ Sports

Former four division world champion Adrien Broner is finally paying off his $1 million jewelry debt ... agreeing to give it all back in 3 installments -- TMZ Sports has learned.

We broke the story ... the boxing star was hit with a lawsuit last year after he allegedly stiffed a jeweler out of more than $1 million in fine jewels.

Pristine Jewelers NY said Broner promised to pay for multiple items which totaled $1.252 million ... but his checks never cleared -- and then he refused to follow through on a payment plan.

But, according to legal documents filed this week ... Broner has finally reached a settlement with the company -- and has agreed to pay off his debt.

Per the details of the agreement ... Broner made his first payment on March 4 and will pay $500,000 by December 31, 2019, and then the final $500,000 no later than 6 months after that.

It's interesting ... according to documents -- Broner struck the agreement with the jeweler on Feb. 15 -- just a couple weeks after he reportedly earned a $2.5 million check from scrapping with Manny Pacquiao.

In that bout, which took place on Showtime Pay-Per-View from the MGM Grand in Las Vegas, saw Pacquiao win a dominant twelve round unanimous decision.