Reformists won 35 of the declared seats. The other 11 announced by the state-run radio went to a hard-line conservative and 10 independents. Twenty seats had not yet been announced.
The hard-line Guardian Council, which oversees elections, still must endorse the results. It annulled a dozen reformist victories in the Feb. 18 first round.
If the Council endorses the latest results and 29 first-round reformist victories in the capital, Tehran, that it has yet to finalize, reformists will control the parliament for the first time since the 1979 Islamic revolution. Reformists won about 70 percent of races in February.
With a simple majority in the 290-seat Majlis, reform-minded politicians could pass laws granting greater social freedoms and weakening hard-liners' grip on key institutions. Hard-liners control the judiciary, military and broadcasting.
But whether the run-off results will seal a reformist victory or open the way to more confrontation isn't clear. Opponents of reforms promoted by President Mohammad Khatami have shown they won't easily give up power.
In the weeks before Friday's vote, the hard-linersalong with annulling some reformist election victoriesclosed 16 pro-democracy newspapers in Tehran and arrested more than a half-dozen top liberal activists.
Khatami's brother, the leader of the largest pro-reform party, called the partial run-off results a clear message to all those people who in the recent months have been resorting to illegal means and seemingly legal pretexts to defeat this promising movement.
It is hoped that everyone would now bow to the vote of the people so that the pure ideals of the Islamic revolution and the programs of the esteemed president will be materialized under national unity and calm and within the law, the state-run Islamic Republic News Agency quoted Mohammad-Reza Khatami as saying on behalf of his Islamic Iran Participation Front.
Reformists maintain that the hard-line crackdown on newspapers and activists could be an attempt to provoke riots that would bring troops into the streets and create a state of national emergency. Such a situation would give hard-liners more time to maneuver.
Some reformists fear that another big election defeat for hard-liners could lead to an attempt to delay the May 27 opening of the Majlis, which constitutionally must be inaugurated on time except in a national emergency.
Khatami has a solid following among Iran's predominantly young population, and the president's pro-democracy allies had been expected to make a strong showing in the run-off.
In all, 132 candidates, including six women, were competing for 66 seats in 52 constituecies in Friday's balloting. Run-offs were needed in constituencies where no candidate received the minimum 25 percent of votes in February. Only the two front-runners from the last round were eligible to contest each seat.
Voting in constituencies where results were annulled was to take place at an as-yet unscheduled time.
By ALI AKBAR DAREINI