New York ? All those junk e-mail messages may promise instant wealth, but they can be quite painful to the bottom line.

A study to be released today attempts to quantify the annual cost of spam: $8.9 billion for U.S. corporations; $2.5 billion for European businesses and another $500 million for U.S. and European service providers.

Marten Nelson, an analyst at Ferris Research, says that while most spam can be deleted in one second, occasionally someone is duped into clicking the message. It also takes time to track down legitimate messages mistakenly tossed by inaccurate spam filters.

Figuring it takes 4.4 seconds on average to deal with a message, the messages add up to $4 billion in lost productivity for U.S. businesses each year.

Another $3.7 billion comes from companies having to buy more powerful servers and more bandwidth as well as divert staff time.