MetroPCS Communications Monday reported disappointing fourth quarter subscriber numbers that sent shares of the company into a nosedive. 

The no-contract carrier saw gross additions of 866,000 subscribers, a 29 percent decrease over the same period last year. The company ended the fourth quarter with approximately 8.9 million total subscribers, which includes net subscriber losses during the quarter of 93,000. 

Churn for the quarter was 3.6 percent compared to 3.7 percent a year ago, down from 3.7 percent in the third quarter of 2012. 

Subscribers operating on the company's LTE network increased dramatically. Fully 2.2 million subscribers were signed up for LTE in the fourth quarter, an increase of 117 percent from the third quarter of 2012.

Shares of MetroPCS sank lower in afternoon trading on the subscriber numbers. MetroPCS stock was trading at $9.51, down 2.26 percent, in afternoon trading. 

MetroPCS is currently awaiting regulatory approval of a merger with T-Mobile USA via an acquisition by T-Mobile's parent company Deutsche Telekom. 

The merger will create what both entities hope will be a stronger competitor. Based on analyst estimates for 2012 furnished by Deutsche Telekom, the combined company is expected to have approximately 42.5 million subscribers, $24.8 billion of revenue.