Sponsorship from private corporations is supporting websites from which Danish students can download essays.
The corporations support the sites through advertising, or provide services free of charge. Massive private sponsorship has made it possible for one of the websites - OpgaveCentralen - to build up a register of more than 8,500 essays. Over a ten-day period earlier this month, the site had 500,000 hits, reflecting a growing trend. A similar site attracts more than 14,000 visitors a month.
It is the many visitors that make the websites attractive to advertisers.
Johnny Damtoft, director of OpgaveCentralen, said: "It's a growing market, and in the future we will expand and do more commercials on the site."
He added that the site should be used only as "inspiration" for students, rather than a means of copying work.
But Michael Brockmann of Texas Instruments said: "At this very moment we are removing our name from the site.
"We don't want our products associated with homework-cheating."
He said the company never directly sponsored the site, though students could download software from the site free of charge.
However, Infopaq, which provides finance and business news for more than 100 of the largest corporations in Denmark, has a sponsorship contract with another site, www.gymnasieopgaver.dk, but has said it will consider its future arrangements with the site.
Netpool, which is owned by worldwide Swedish telephone company Telia, delivers commercials to OpgaveCentralen. Netpool manager Hans Ulrich Pahl promised: "We will look into this, and discuss the problem of students cheating."
Following the revelations, the Swedish internet-shopping company TOGA.com and Scandinavian publishers Egmont Entertainment are considering removing all their commercials from OpgaveCentralen.
Both companies claim that Netpool is responsible "for the unfortunate placement of commercials" on the sites.