3 MIN. DE LECTURA
(New throughout, adds comment from Scioli, analyst, updates results and financial market activity)
BUENOS AIRES, Aug 10 (Reuters) - Argentina's presidential race was wide open on Monday and likely to be settled in a run-off vote after primaries indicated ruling party candidate Daniel Scioli did not have enough support to win outright in the first round.
The prospect of a head-to-head between Scioli and his more business-friendly rival, Mauricio Macri, sent Argentine bond prices higher, with defaulted U.S. dollar discount bonds hitting a two-month high.
Macri has promised to unravel swiftly outgoing President Cristina Fernandez's controls on the economy to free up the market. Scioli advocates gradual change but his defense of leftist Fernandez's policies led opponents to question his credentials.
Scioli, who will need woo undecided voters, said he would not shy away from making policy corrections needed to further the development of Latin America's No. 3 economy.
"Our idea is to maintain the policies that need maintaining, correct the policies that need correcting and deepen those that need deepening," Scioli told a news conference on Monday.
With 98 percent of votes counted, official results showed Scioli, who ran unopposed for the ruling Front for Victory party's ticket, winning 38.41 percent. Macri's Let's Change alliance secured 30.07 percent of votes.
A candidate needs 45 percent, or 40 percent with a 10-point margin over the second-place candidate, to win the first round of the election outright on Oct. 25. Argentina's primaries allow voters to cast ballots across party lines and so provide an accurate account of public opinion ahead of the first round.
"Scioli will launch a huge effort to increase his share of votes ... which means that he will moderate his stance," said Daniel Kerner of Eurasia Group.
In early trading, Argentina's defaulted 2033 U.S. dollar Discount bonds rose as much as 1.47 percent to a two-month high of 100.917 before easing off, Thomson Reuters data showed.
Argentina's benchmark Merval index was up 6 percent late in the afternoon.
Opinion polls are split on who would win a close-fought second round run-off. How the votes of third-placed candidate, dissident Peronist Sergio Massa, are split will be key.
Macri told supporters late on Sunday night that "an alternative path toward change in Argentina is consolidating." (Reporting by Richard Lough, Sarah Marsh and Nicolas Misculin; Editing by Bernadette Baum and David Gregorio)