Microsoft has said it is taking the first steps to comply with a ruling by US regulators to prevent anti-competitive behaviour.

The software giant plans to reveal nearly 400 units of computer code - known as application programming interfaces (APIs) - and previously secret internal operating rules, by the end of August.

The disclosures would allow computer makers to create machines with less dependence on Microsoft software, as well as develop programs that could work within Microsoft's Windows.

The move follows an agreement between Microsoft and US anti-trust lawyers in November, after the software giant was charged with monopoly tactics that prevented healthy competition.

Sceptics hold firm

Microsoft said it was "erring on the side of reasonableness" by making these changes, adding that it was updating some of its Windows titles to so that users could remove unwanted Microsoft features.

However, the changes were criticised by some.

Ken Wasch, head of the Software & Information Industry Association, said: "[Microsoft] are still retaining for themselves complete control over what they release, when they release it, and what is suitable subject matter for release."

Deal yet to be agreed

Microsoft's concessions are being reviewed by the Justice Department to see if they are enough to comply with last year's ruling.

Microsoft was being sued by 18 US states for anti-competitive behaviour, and reached an agreement with lawyers and half the states to make changes.

The other nine states are still pursuing the case.