Our correspondent learnt that he will perform the act at noon.
It will end speculations that the President may withhold assent again.
The National Assembly transmitted the bill to him for the second time on January 31 after reviewing it.
President has a 30-day window within which to either assent or withhold assent.
Sources said arrangements have been concluded for the signing.
“All these anxieties will disappear by Friday afternoon. He will be signing the bill around noon of that day.
President Buhari cited the cost of conducting direct primary elections, security challenges and possible manipulation of electoral processes as part of the reasons for withholding assent last November.
“Secondly, we have discovered another reason the APC and their allies are now putting pressure on President Buhari not to sign the Electoral Act as re-amended in line with President Buhari’s demands.
“The APC finds clause 84 in the amendment unfavourable to the party. According to Clause 84 of the transmitted bill, ‘No political appointee at any level shall be a voting delegate or be voted for at the convention or congress of any political party for the purpose of the nomination of candidates for any election’.
“The implication is that all political appointees in President Buhari’s government would no longer be eligible, either as voting delegates or aspirants during the conventions or congresses of their political parties.”
But, Chairman, House Committee on Defence, Babajimi Benson, said the controversial Clause 84 (10) only seeks to create a level plain field for all aspirants.
He said the provision does not require appointees to resign before participating in conventions and congresses.
“Even if it does prevent political office holders from running, there’s a provision in the constitution that protects them,” the lawmaker added.
Imo State Governor, Hope Uzodimma, described as unnecessary the worries expressed by some Nigerians over the perceived delay.
He told reporters: “To give Nigerians the best, the President has to study the Amended Act before signing it into law.
“If in the process he discovers things in the Act that are not in the interest of the people of Nigeria he has the constitutional mandate to move it back to the National Assembly for corrections before his assent.”