In preliminary proxy statement filed with the Securities and Exchange Commission today, MetroPCS (TMUS -0.08%) gave notice of a special shareholder meeting on March 28 for the purpose of voting "on matters relating to the combination of MetroPCS with T-Mobile USA."

The MetroPCS board of directors voted unanimously to approve the merger deal that the two companies agreed on last Oct. 12.

MetroPCS will be seeking shareholder approval of such tenets of the deal as receiving a cash payment of $1.5 billion from T-Mobile in return for giving up 74% of MetroPCS' shares.

There has been criticism of the deal from some shareholders, including from P. Schoenfeld Asset Management, a fund that owns 2% of MetroPCS shares. PSAM filed a preliminary proxy statement with the SEC last week stating that it plans to oppose the merger.