One of Miami’s fastest growing technology companies will merge with another local start-up.

Unified Payments, ranked No. 1 in Inc Magazine’s 2012 list of the fastest-growing companies in the country, has signed a deal to be acquired by Net Element. Unified Payments’ CEO, Oleg Firer, will become CEO of Net Element. Both are based in the Miami area and deal with online payments — Net Element abroad and Unified in the United States.

Terms of the deal were not disclosed, but securities filings show Net Element agrees to acquire Unified’s $23 million in debt.

In an interview, Firer said the two company’s expertise in the latest developments in online payments, as well as their reach around the world, will give Net Element a stronger hold on the market.

“Anything involving emerging technology for payment systems is going to be our niche,’’ he said.

DOUGLAS HANKS