Shares in mobile phone and computer chip maker Imagination Technologies rocketed on Tuesday after the firm reported a 52% surge in adjusted pre-tax profit, alongside strong licensing and continued royalty revenue growth.Adjusted pre-tax profit rose to £15.3m for the six months to 31 October 2011 from £10.1m the year before. Group half-year revenue was up 28% to £56.3m.Technology revenues increased 41% to £42.6m, licensing revenues soared 65% and royalty revenue jumped 26% or 29% on a US dollar basis. Imagination said the tough retail environment in the UK was offset by strong overseas growth.Looking ahead chief executive Hossein Yassaie said, "Whilst acknowledging the on-going challenges to the global economy, we remain confident of our continued good progress in the current financial year and beyond, given the fundamental strengthening of our business on the back of a very active and growing pipeline of licensing prospects, the growth in design wins and the momentum in our chip volume."Evolution Securities analyst Philip Sparks expects growth to accelerate in the second half, highlighting the "outstanding feature in these results" as the 65% increase in license revenue."Imagination's FY11 numbers may have fallen slightly short of expectations, but judging by the 1H12 figures out today, that result looks to have been a minor aberration on the long-term growth trend...We think upgrades are back on the agenda," Sparks said.Shares were trading 11.6% higher at 487.7p by 12:51, after hitting 502.3p earlier on. This surpassed (briefly) the stock's current 52-week closing high of 502p reached back in June.--cj