The National Consumer Council (NCC) has accused Microsoft and other leading software companies of forcing consumers to sign "unfair" licence agreements when buying software.

The NCC charged 17 of the world's biggest software companies, including Symantec and Adobe, of using end user licence agreements to mislead customers into "signing away their legal rights" leaving them with "less protection than when they buy a cheap biro ".

Users are typically unaware of what they are agreeing to until after they have bought the software, according to the consumer group.

The NCC has now called on the Office of Fair Trading to launch an investigation into the matter.

Other companies singled out for blame include Apple, Chief Architect, Magix, Nero, Corel, Sega, Nova Development, Britannica, Sonic Solutions, Twelve Tone Systems, THQ, GSP, McAfee and Kaspersky.

The NCC looked at 25 software products, including Office 2007, Corel WordPerfect Office X3 and Adobe Photoshop CS 2, as part of its report entitled Whose Licence Is It Anyway? (PDF)

Fourteen of the products failed to mention on the packaging that users must accept a licence agreement when installing the software. Only four of those that did provided a link to a copy of the agreement.

"Plugging the gaps in the EU consumer rights and protection framework is a vital move," said NCC senior policy advocate Carl Belgrove.

"Consumers cannot have a clue what they are signing up to when some terms and conditions run to 10 or more pages. There is a significant imbalance between the rights of the consumer and the rights of the holder."

Microsoft has declined to comment as it had not yet seen the details of the report. But the company claimed to be committed to dealing "fairly" with consumers and addressing any concerns they might have.