Electoral officials on Sunday said none of the 11 contenders received the minimum 50% plus one vote needed to win and become head of the powerful Journalists' Union.
The union has increasingly become politicised, hosting a number of pro-reform rallies before Egypt's 7 September first contested presidential poll.
Groups such as the Kefaya (Enough) movement frequently staged protests in front of the union building demanding an end to President Hosni Mubarak's 24-year rule and other similar groups used the premises for seminars.
Incumbent union boss Galal Aref from the Akhbar al-Yom publishing house and fellow candidate Ibrahim Hegazi from the al-Ahram publishing house emerged as the frontrunners and will face each other in a runoff vote on Thursday.
Many of the candidates had campaigned on a platform promising to hasten the abrogation of a 1995 press law that journalists said turned them into criminals because of the prison terms it prescribed for libel.
Ibrahim Hegazi was one of two
frontrunners in the union vote
They also pledged to campaign against other laws they argue restrict freedom of the press in a country where there are only few independent newspapers and the state has absolute control over the airwaves.
More than 3000 journalists participated in the election.
The banned but tolerated Muslim Brotherhood and its Islamist allies took control of the country's powerful professional unions through elections in the mid-1990s and the state responded by disbanding those unions.
They included the Lawyers' Syndicate and the Engineers' Syndicate.
The government considered this an attempt by the Brotherhood to gain legitimacy through the back door, and parliament later passed a law that was primarily aimed at limiting Brotherhood gains in the future.