BRASILIA (Reuters) - Pro-business candidate Aecio Neves has overtaken environmentalist Marina Silva in voter support ahead of Sunday's election and would face President Dilma Rousseff in a likely second-round runoff, a new poll showed on Saturday.
Rousseff would win the runoff by 46.0 percent of the votes against 40.8 percent for Neves, the survey by polling firm MDA said.
In first-round voting, leftist incumbent Rousseff has 40.6 percent voter support, and Neves has moved into second place with 24 percent, ahead of Silva who is now third with 21.4 percent.
The difference between Neves and Silva is within the margin of error of the poll, but MDA said the trend was firm because Neves' rejection numbers have come down markedly. The polling firm projects that the presidential election will be decided in a runoff between Rousseff and Neves.
If no candidate wins an outright majority as expected in the first round on Sunday, the election will be go to a runoff between the top two vote-getters on Oct. 26.
The MDA poll commissioned by the transport industry lobby CNT surveyed 2,002 people between Thursday and Friday and has a margin of error of plus or minus 2.2 percentage points.
(Reporting by Anthony Boadle; Editing by Alison Williams)