FRANKFURT, Germany — Eight of 90 European banks flunked stress tests projecting how they would fare in another recession, and 16 more barely passed — but analysts doubted Friday's results would succeed in restoring confidence in the continent's shaky financial sector.
Some countries challenged the results as inaccurate and overly pessimistic, saying they would not force their weaker banks to raise new cash.
Economists warned that the tests were insufficient because they did not simulate the main risk hanging over Europe: a default by Greece.
While markets were sanguine about the results — the euro barely moved — experts questioned whether the tests achieved their goal: restoring confidence in a sector that is carrying billions of bad debt from crisis-hit countries like Greece, Ireland and Portugal.
"The publication of these results will not assuage investors' fears over the resilience of the EU banking sector," said Marie Diron, senior economic adviser for Ernst & Young.
She said the tests were useful to single out particularly weak banks, but noted that a national debt default was "the single greatest risk facing the European banking sector at present."
As it presented the results, the European Banking Authority said the failing banks should quickly raise a total of $3.5 billion to boost their capital cushions. Banks that barely passed also were asked to shore up their finances.
Spain, commonly seen as the next-weakest link in the 17-country eurozone, fared by far the worst in the tests.
Five banks — Catalunya Caixa, Caja de Ahorros de Mediterraneo, Banco Pastor, Unnim and Group Caja3 — failed the test outright, while seven others barely scraped by. However, the number of banks that Spain tested was far higher than in all other countries.
The next in line was Greece, with two lenders — EFG Eurobank and government-owned ATEBank — flunking the tests and two others almost failing.
The European Banking Authority lacks the power to force banks to raise more capital — whether from investors or governments — or to make them merge or sell businesses.
Only national governments can do that, and analysts say the key to the stress tests is whether governments act on the results.
"The real test of the process, and of the strength of the new European supervisory system, will be the willingness of individual regulators to follow up," said Bob Penn, a partner at commercial law firm Allen & Overy.
In addition to the Spanish, Greek and German banks that barely passed, one bank in Slovenia, one in Italy, one in Cyprus and two in Portugal just survived the stress scenario.
The European Banking Authority worked hard to make this year's test more credible after a stress test last summer was largely considered a whitewash — it failed to spot huge black holes in Irish lenders, whose collapse weeks later pushed the country to take an international bailout.
A similar exercise in the U.S. in 2009, however, is widely credited with drawing a line under the country's banking crisis.
In the U.S. stress tests, 10 of the nation's 19 largest banks had to raise a total of about $75 billion.
The European Banking Authority said Friday that the main reason so few banks failed the test was that it gave lenders the opportunity to raise capital ahead of the result's release. At the end of last year, 20 banks would have failed the tests and between January and April lenders raised a total of $71 billion in preparation for the test.
The banks were also required to maintain a bigger financial pad than last year: at least 5 percent of their loans, investments and other risky assets.