The report, a joint effort between GfK and mobile social network Limbo, surveyed 1000 users in the U.S. and 1000 in the U.K.

The preliminary findings, which werepresented at a medical conference, raise the possibility that overuse of gamingdevices and mobile phones could impact children's joint health, the researcherssaid.

Nine years ago, the two Iberian firms launched a united assault on Brazil, forming a joint venture from seven assorted mobile units that they already controlled.