Cellino met with the potential buyers, led by Italian businessman Luca Silvestrone, in Miami on Tuesday afternoon to finalise the agreement.
The deal, worth a reported 85million euros (£69m), is expected to be completed by the end of the week.
"I am delighted," Cellino said to Gazzetta dello Sport. "We have reached an agreement and we have signed a letter of intent that foresees their takeover of the club.
"Now they will have to fight with the (Italian) bureaucracy.
"I hope they will be allowed to do what I wasn't given permission to do (to build a new Cagliari stadium)."
Cellino purchased Cagliari in 1992 and had been looking to sell the Sardinia-based club since acquiring a 75 percent stake in Leeds earlier this year.
Should the sale go through, Cagliari would become the third Serie A club to be foreign-owned - Roma have been controlled by an American consortium since May 2011 while Indonesian tycoon Erick Thohir acquired Inter Milan last year.
Cagliari finished 15th in the Serie A standings, seven points clear of the drop zone.