LONDON — Ninety-one banks. Twenty-seven countries. One exam. So who's going to flunk the European stress test?

Markets were on alert today, waiting for regulators to publish their investigation into the financial health of Europe's banking sector. The goal of the tests is to allay market fears the banks are in trouble after a global recession and the discovery that many European countries were carrying too much government debt.

Although most of the banks are expected to get the all-clear, there is a great deal of market concern the tests are not as stringent as they should be.

Little is actually known about how the London-based Committee of European Banking Supervisors is conducting its analysis — in marked contrast to the U.S. banking tests that demanded more than half the U.S. banks shore up their reserves.

The key unknown is what potential losses the CEBS assumes banks will have to absorb from losses on investments in government debt, notably those from Greece, Portugal and Spain — the three countries considered the most financially shaky.

What is known about the test is that the CEBS is assuming that EU economy will suffer another recession. That is significantly worse than the EU Commission's forecasts, which predict the EU economy will grow by 1 percent this year and 1.7 percent in 2011.

The general consensus in the markets is that around 10 European banks will fail the tests no matter how they are designed, with the small Spanish savings banks — the so-called cajas — and the regional German banks —the Landesbanken — most at risk. Failing the stress test won't mean the banks are bust, but that they will need to raise money from investors or governments.

The finances of the cajas were hit by the collapse of a Spanish construction and property boom, while the German banks made oversized bets on global financial markets before the 2008 meltdown.