A shortage of mobile software development skills has driven contractor salaries up by 16 per cent in the past 12 months, the fastest increase since the 1990s dot com boom.

But the struggle to recruit the right staff is just the latest manifestation of a repeated problem in the IT industry.

The growing popularity of BlackBerrys and other 3G mobile services has increased hourly rates for content developers from £37 to £43, says research from SkillsMarket and the Association of Technology Staffing Companies (Atsco).

The problem is that employer training fails to keep up with technology trends, said Atsco chief executive Ann Swain.

The latest shortfall is for developers with skills in wireless technologies such as Bluetooth and .mobi, which allows web sites to be tailored for mobile devices.

‘These mobile skills are in short supply because companies have not trained their staff,’ said Swain.

Skills shortages bite particularly hard on the technology industry because new developments can reach their peak in as little as 18 months.

It is always up to employers to train staff in new technologies, but most firms lack recruitment planning, said Swain.

‘Instead companies have the knee-jerk reaction of hiring contractors, rather than solving a recurring recruitment problem,’ she said.

The dilemma is that companies are loath to spend money on training only for staff to leave.

To safeguard their investment, employers should consider training contracts which oblige staff to stay a specific time, said Philip Virgo, strategic adviser to skills group the Institute for the Management of Information Systems.

‘Training contracts are very valuable when employers need to train staff quickly,’ said Virgo.

But not everyone agrees that training is the employer’s responsibility.

Acquiring new skills is often up to the individual, said John Eary, a senior consultant at IT services company NCC Group.

‘Talented, well-rounded IT professionals should be able to keep themselves up to date and should need less formal training,’ said Eary.

But turning to contractors in the short term can make sense because their peripatetic working lives help them pick up new skills, he said.