While France has devised a plan to roll over Greece’s debts and the Greek parliament -- in the face of a national strike and major protests -- just passed austerity measures requested by the European Union, these early signs that worst of the Greek debt crisis is over doesn't mean investors can relax and assume all is well.

Standard & Poor's analyst Ken Leon says investors holding certain exchange-traded funds (ETFs) that have significant hidden exposure to Greek debt still need to be alert.

"We don’t see a high level of risk at this moment,” said Leon, “but we thought it prudent to point out the holdings.” 

In a report issued this week, Leon and a team of S&P ETF analysts wrote that the sovereign debt risk for Greece led European regulators to mandate higher reserve requirements for major European banks which would, in turn, affect their performance and pose additional risk to investors holding any ETFs that included those financial institutions.

The Greek crisis has also helped drive down European shares as a group. So much so in fact, that by late June, the S&P Euro 350 Index had lost 10% of its value in less than three months compared to a single-digit decline for the U.S. S&P 500 over the same period.

Leon singled out several ETFs for having particularly high Greek debt exposure.

The most exposed, he says, is the iShares MSCI EARE Index Fund. This fund is 22.65% invested in financial holdings, with another 12.04% in diversified banks.

Next in terms of Greek exposure, according to Leon, is the Vanguard MSCI Europe ETF, which has 21.29% of its holdings in the financial sector with another 11.4% in diversified banks. 

Two other ETF’s with significant exposure, Leon said, are the iShares S&P Europe 350 Index Fund, and the iShares MSCI EMU Index Fund, each with financial sector exposure of about 22%, plus diversified bank holdings of another 11-12%.

Leon said, “We think the actual exposure to Greek debt in these ETFs is probably not more than 5%.” 

While that may not mean disaster, should the current rescue plan fall through or should the crisis return, Leon says “investors should be aware of the risk.”

S&P equity analyst Alec Young recommends that investors monitor their exposure to Greece, and while he favors holding European equities, he says investors for now should “avoid financials.”