Hewlett-Packard is splitting into two companies, using a breakup to become nimbler after failing to keep up with the shift away from the printing and personal computing businesses it pioneered.

The US justice department has opened an investigation relating to Autonomy Corp after Hewlett-Packard accused the software company of misrepresenting its performance before being bought last year.

HEWLETT-PACKARD last night forecast first-quarter profit that missed analysts’ estimates, a sign that chief executive Meg Whitman may struggle with the slump that led to the ousting of her predecessor, Leo Apotheker.