Reuters is reporting that foreign investors — discouraged and anxious about the debt incurred by Greece and the ensuing problems of other Euro zone economies as the result — are turning to U.S. mortgage-backed securities as a viable investment option.

From January 2009 to March 2010 — as a way to spur the housing market — the U.S. Treasury Department bought up more than $1.4 trillion in assets, making it unattractive to overseas buyers at the time. But since the government got out of the securities buying business, foreign investors have been laying down their money — Euros, drachmas, pounds, krones, etc. — and it shows.

According to Reuters, foreign central bank ownership of U.S. Treasuries and agency debt has increased over the past 12 weeks to approximately $789.2 billion. This is up from last week’s figure of approximately $785.6 billion. Since the beginning of this year, overseas central banks purchased $20 billion in Treasuries and debt.

Last week, despite protests from its constituents, the Greek government passed a $40 billion austerity bill in exchange for approximately $150 billion in aid from the European Union and the International Monetary Fund. However, that will not be enough to allay foreign investors’ fears, saying this problem could spread to other Euro zone economies.

With foreign buyers plugging the hole in mortgage-backed securities purchases left by the federal government, this could help mortgage rates stay low — which is the reason the Feds bought up these assets in the first place. It’s just that these securities are now under different ownership.