Vendors are still struggling to shift tablet PCs, which currently represent less than one per cent of notebook sales - and Microsoft is getting the blame, according to analysts.

UK analyst firm Canalys argued that current low sales should not come as too much of a surprise and suggested that Microsoft, through its hardware partners, needs to put much more effort into pushing the category forward, particularly in EMEA.

"No one expected tablets to hit huge volumes overnight, but the shipments to date have fallen short of even the most conservative estimates and Microsoft needs to do something about it," said Canalys director and senior analyst Chris Jones.

Jones added that the smaller form-factor ultra-portable notebooks only account for between five and 10 per cent of most vendors' notebook shipments.

This is because most users remain reluctant to compromise features for increased mobility, and all current tablets fall into this category.

The research also indicated that the market for more specialised pen-based devices, such as those offered by Symbol and Intermec, is only around 50,000 units per quarter in EMEA.

For tablet PC shipments to exceed this will need to break out of vertical niches and provide more mobile professionals with a compelling proposition.

According to Canalys analyst Rachel Lashford, tablet sales have been further hampered by the weak state of the economy and restrictions on IT spend, particularly on new, more adventurous projects where the return on investment is not proven.

"The first year was always going to be slow, but it is particularly disappointing that shipments have declined this quarter," she said.

"The fact that most vendors are only offering a single model, and that Microsoft isn't pushing the concept as hard as it could, coupled with the absence of key notebook vendors, such as Dell, IBM and Sony, leaves potential buyers with doubts over the industry's commitment to the format, and those doubts will hurt sales."