Qualcomm Inc. said Friday it is again extending the offering period for its cash tender offer for all of the shares of NXP Semiconductors N.V. The offering will now expire at 5.00 p.m. on May 25. The move marks at least the 11th time Qualcomm has extended the offer this year. Qualcomm shares are down 0.5% in the last 12 months, while the S&P 500 has gained 14%.