Qualcomm has extended its $110-per-share cash offer for all outstanding shares of NXP to 5pm EST, on 12 January, 2018.
The multinational semiconductor and telecoms equipment company is in the middle of a fight with the European Commission to clinch the $39bn takeover deal for rival NXP Semiconductors.
The Commission is concerned the transaction could lead to higher prices, less choice and reduced innovation in the semiconductor industry.
In November, Bloomberg reported that European approval may be forthcoming by the end of the year.
The proposed merger has already been approved by US antitrust authorities.
Qualcomm has a market cap of $77bn and had earnings of $6.5bn in 2016.