Headline group growth at Experian missed analysts' forecasts on Thursday, but Shore Capital's Robin Speakman applauded the stronger-than-expected third-quarter performance from the core credit services division.The broker maintained a 'buy' rating for the stock.Information services company Experian reported flat organic revenues in the third quarter, compared with Shore's +2% expectation."The data services specialist continues to report mixed trading patterns across the group, impacted by a number of short-term trading items offsetting strong performances in the core credit divisions across the regions," Speakman said.Speakman said the analytics unit had a "tough" quarter with organic growth of just 1%, and this was responsible for the group performance below below forecasts.There was also weakness in marketing, where organic revenues declined 1%.Meanwhile, consumer services organic revenues dropped 12% as the re-launch of the service set in North America continues to weigh. Speakman said: "We expect to see a couple more negative quarters here yet, but on an improving trend before the headwind blows out in the summer months of 2015."However, credit services delivered organic growth of 6% over the quarter, helped by 7% and 6% increases in North and South America, respectively, both of which came in ahead of forecasts.The stock was up 3.3% at 1,100p by 11:18.