The commanding centre half has been hugely impressive since arriving at Goodison Park on a season-long deal from Marseille.
His marshalling of the Toffees defence has played a pivotal role in the club's surprise climb into third in The Premiership.
Toffees boss Moyes was eager to make Yobo's stay on Merseyside permanent and the club do have first option on the African powerhouse.
But rather than wait until the end of the season, Everton are primed to wrap up the deal imminently to prevent any vultures swooping in for Yobo's talents.
"The two clubs have agreed a deal with Marseille over Joseph Yobo," Moyes told the club's official website.
"We have been working hard to try and finalise the deal and the board at Everton have been fantastic in putting the finances in place.
"There are still one or two matters to be sorted out with Joseph and his advisors but we hope to conclude the deal in the next couple of days."
The final fee is expected to be £4.5 million with Everton already having paid £1 million to take Yobo on loan.
Marseille chairman Christophe Bouchet was pleased with the outcome which will swell his club's coffers.
"This is an excellent financial operation for l'OM," confirmed Bouchet to the club's official website.
"In respect of our budget for May, this does not consitute a providential contribution to our accounts.
"On the other hand, this transfer will allow us to present proof to the DNCG on December 5 that we have realised the promises we made."
