Sprint Corp. shares fell in the extended session Friday following reports the telecom is close to announcing plans to merge with T-Mobile US Inc. Sprint shares fell 7.9% after hours, following an 8.3% rise to close at $6.50 in the regular session. T-Mobile plans to offer $6.50 a share for Sprint, or about $26 billion, as soon as Sunday, according to reports from the Wall Street Journal and CNBC. Shares of T-Mobile were up 0.8% after hours. A tie-up between the two telecoms has been making the rounds lately following a renewal of merger talks recently.