Spanish Prime Minister Mariano Rajoy said Friday's summit here of the leaders of the euro zone's four biggest economies - a meeting in which a proposed stimulus package for the region was unveiled - produced a consensus about the need to preserve the single currency.

"There was an undeniable commitment to the irreversibility of the euro, which is the most important project we Europeans have undertaken," Rajoy said at a joint press conference after his meeting with Italian Premier Mario Monti, German Chancellor Angela Merkel and French President François Hollande.

Following the gathering, held ahead of next week's European Council meeting in Brussels, the four leaders unveiled a proposal for a 130 billion euro ($163 billion) stimulus package - equivalent to 1 percent of the euro area's gross domestic product - to spur growth.

"At (next week's EU summit), we'll propose measures to jumpstart the economy with investments," Monti said at the press conference, mentioning the 130-billion-euro figure.

The leaders did not provide details on the growth measures nor indicate the origin of the proposed stimulus funds.

Rajoy, for his part, said the stimulus measure would be complemented by a move toward greater euro zone integration in the political, banking and fiscal spheres, and that the countries would not ignore their commitment to keeping a rein on budget deficits - a top priority for Germany.

"We made a clear and forceful commitment to the future of Europe. We want more Europe, we want a political union, we want an economic union, we want a banking union and a fiscal union," the Spanish prime minister said.

Rajoy's administration will formally submit its request for euro zone financial assistance for its ailing banking sector on Monday, but it is still seeking to have that aid channeled directly to those institutions rather than via the government, Economy Minister Luis de Guindos said Friday in Luxembourg.

When European finance ministers agreed on June 9 to extend a lifeline of up to 100 billion euros ($126 billion) to Spain's banks, they decided to channel the loan through the government, and specifically Spain's state-backed Fund for Orderly Bank Restructuring, or FROB.

Indeed, that is the only possible route under current euro zone rules, but the Spanish government - which is ultimately responsible for repayment of the loan - has lobbied for a direct cash injection to the banks so those funds do not increase the country's public debt burden.

Due to investors' concerns about the higher debt load, Spain was forced to pay sharply higher interest rates in bond auctions this week.

The yield on Spain's benchmark 10-year bond in the secondary market, meanwhile, surged above 7.3 percent - the highest level since the adoption of the euro - early this week although it has fallen sharply in recent days as investors grew more optimistic that euro zone policy-makers can solve the long-running debt crisis.

Though opposed by Germany, direct bank recapitalization is supported by the European Commission and the International Monetary Fund, which on Thursday heaped pressure on Berlin to sever the link between banking and sovereign risk.

Spain was forced earlier this month to seek a euro zone rescue of its ailing banks due in large part to its spiraling borrowing costs.

On Thursday, the results of two separate audits of Spanish banks carried out by the consulting firms Roland Berger and Oliver Wyman showed that the country's bad loan-saddled lenders will require between 51 billion euros and 62 billion euros in additional capital under a worst-case scenario in which Spain's cumulative gross domestic product were to fall by 6.5 percent between 2012 and 2014.

According to the deputy governor of Spain's central bank, Fernando Restoy, the consulting firms found that the funding needs will be concentrated at banks that have already received assistance from the FROB, including BFA-Bankia, CatalunyaCaixa, Novagalicia and Banco de Valencia.

The country's largest banks, Banco Santander, BBVA and CaixaBank would not need additional capital even under the worst-case scenario, while a third group comprising seven financial institutions could raise the money by their own means or with some type of moderate state assistance.

Restoy, said that, based on the firms' audits, the European lifeline would be more than sufficient to stabilize Spain's most troubled banks.

Spain's banks have been hard hit by the collapse of the country's 1995-2007 real estate boom, which has left them saddled with toxic property assets.

Recently nationalized BFA-Bankia - the country's No. 4 financial institution - is seeking what would be the largest bank bailout in Spanish history after saying on May 25 it needs another 19 billion euros to boost loss provisions.

The 2008 global financial meltdown came as Spain was struggling with the bursting of the property bubble. The ensuing slump has led to numerous business failures and pushed the country's jobless rate above 24 percent.

Nearly half of Spaniards under 25 are jobless and tens of thousands of families have been evicted from their homes after falling behind on their mortgages. EFE