Qualcomm’s agreements with two major Chinese customers are taking longer than anticipated, Chief Executive Steve Mollenkopf said on a conference call. President Derek Aberle said some Chinese customers were “improperly withholding” royalties on Qualcomm’s patents by changing the way they report sales. The company, which got half of its fiscal 2014 revenue from Chinese customers, said it expected the issue to be resolved once the new agreements were completed.