By REUTERS

BUENOS AIRES, Argentina, Oct 15 (Reuters) - President Fernando de la Rua said on Monday there were ``no fundamental changes'' in
the balance of power in Argentina despite voters punishing his ruling coalition in mid-term Congress elections.

Opposition Peronists, who previously controlled the Senate and were a second minority in the lower chamber, looked set to to become the
biggest party in both houses of Congress after Sunday's vote.

Partial results showed 15 percent of the nearly 25 million voters turned in spoiled or blank ballots, a sign of growing skepticism that
politicians, seen as corrupt, can save the economy from a slump that is now entering its fourth year.

But while analysts said De la Rua would have to forge a wider political consensus to keep in place his cornerstone austerity drive to allay
fears of default on a $132 billion public debt, the president said not much had changed.

``There are not any fundamental changes,'' De la Rua said before leaving on a trip to Spain, adding that the Peronists had a Senate majority
before the vote. He has already renewed his commitment to unpopular austerity plans after the vote.

The opposition, though, said De la Rua would have to listen to the ballot results.

``I believe the president will understand (the result). The result is so overwhelming, not just for Peronists but for the null votes,'' Eduardo
Duhalde, a leading Peronist victor in the Senate, told reporters.

Official results showed the Peronists forming the largest bloc in the 72-seat Senate with 35 members but down from 40 while the Alliance
added three Senators for a total of 26 compared to 23 before Sunday's elections.

The count continued in San Juan province where both parties were neck-and-neck for three seats up for renewal, Interior Minister Ramon
Mestre said.

Otherwise, the provincial parties were whittled down to seven members from nine in the upper chamber and the fledgling Alternative for a
Republic of Equals returned one senator.

``This is a Congress that will be in opposition hands, but we're not going to make (De la Rua) toe the line because that would lead to a worse
tragedy than we have now,'' Duhalde said.

Investors saw De la Rua's pledge to end deficit spending as key to allaying fears Argentina could default, worries that rocked world markets
this year.

Treasury Secretary Jorge Baldrich said the government would probably announce this week some economic measures, expected to include a
voluntary debt swap to ease a liquidity crunch.

With 98 percent of polling stations counted, Peronists won by a huge margin -- more than 20 percentage points -- in the Senate race for
Buenos Aires province, the wealthiest region and home to a third of Argentina's 37 million inhabitants.

Duhalde won 37.5 percent of the contest for the Senate against 15 percent for former President Raul Alfonsin, who secured the second of
three seats for the province. About 21 percent of votes were spoiled or left blank.

That vote pattern was repeated in many regions in the election to renew the entire national Senate and half the lower house at the midpoint of
De la Rua's four-year term. In some provinces, the spoiled and blank votes reached 40 percent.

AUSTERITY AT RISK?

Pessimists said the results meant the president would be unable to keep austerity plans given his stronger opponents.

Some analysts expected more social protests from Argentines tired of a recession during which their beloved soccer clubs have gone broke
and many people fear for their safety.

But markets were calm. Argentina's benchmark Global 2008 dollar bond rose 0.917 percent to 55 points in afternoon trade on Monday.

``We believe governability will not necessarily be weakened by the Alliance defeat, as the executive might find it easier to negotiate with the
Peronist governors than with its own party members,'' said Pablo Goldberg, an emerging market analyst at Merrill Lynch.

Optimists said Peronists had proven themselves willing to help the government and pointed to the fact that some of De la Rua's critics from
within his own coalition -- such as the more leftist Alfonsin -- had also been punished in the vote.

``The Peronist party contributed much to governability, more than some in the Alliance,'' Cristiano Ratazzi, head of the auto manufacturers
association ADEFA, told Reuters. ``The result of the elections does not seem bad for the government.''

Peronists, who governed the country from 1989-1999 under the free-market pragmatism of former President Carlos Menem, have allowed
austerity plans to pass the Senate they controlled while still being vocally critical of De la Rua.

De la Rua, whose rule since 1999 has been mostly an exercise in disaster management as one financial crisis piled upon another, promised to
stick to the austerity drives.

``There is something that has not changed (after the elections), and they are the reasons for which I was elected president ... to finish with
excessive public spending and achieve a balanced budget, without deficits,'' De la Rua said in a televised speech on Sunday night.

Local media and political analysts expected the president to soon announce Cabinet changes but they would likely be cosmetic. The
government has said the centerpiece of the executive, Economy Minister Domingo Cavallo, will stay.

Cavallo has struggled to make the economy grow since he was appointed in March but he has a few tricks left, including the voluntary debt
swap with local banks and pension funds.