Facebook Instagram deal 'delayed by investigation' The postponement of finishing the acquisition, because of the competition investigation (a routine procedure in the US for any deal worth more than $68.2m), which will entail Facebook's closest rivals (including Google and Twitter) providing information about the deal, could also set back the social network's mobile ambitions. "We believe this increased usage of Facebook on mobile devices has contributed to the recent trend of our daily active users increasing more rapidly than the increase in the number of ads delivered," Facebook said. As more people use mobile devices to chat to friends and post pictures yet Facebook remains unable to make money from them, "our financial performance and ability to grow revenue would be negatively affected," the dominant social network admitted. Facebook made the disclosure in an update to its regulatory filings, ahead of its highly-anticipated IPO next week. The flotation is expected to raise as much as $13.6bn on a valuation of up to £96bn. Competition analysts believe the Facebook-Instagram deal will ultimately be approved - but it could take up to 12 months to clear. Special attention will be given to the takeover because of the high price Facebook paid for the app, which has yet to generate any revenues. "They're going to want to take some months to investigate and understand the market and other players," Mark Lemley, a professor at Stanford Law School, told The Financial Times. And there may be more parties with an interest in submitting information.