The U.S. Federal Communications commission could reach a decision by the end June about whether to give its go-ahead to Sirius Satellite Radio Inc's acquisition of XM Satellite Radio Holdings Inc

The commission could act by the end of the second quarter, said FCC Chairman Kevin Martin at a press conference in Washington on Friday, according to Bloomberg.

Martin would not discuss details of the commission's deliberations.

While the initial value of the proposed all-stock deal was $4.6 billion in February it has fallen to $3.9 billion.

The U.S. Department of Justice has already given its approval to the deal, saying the combined company would not create a monopoly in the market.

Shares of Sirius closed down 4 cents, or 1.52 percent to $2.59. XM shares fell 2 cents, or 0.18 percent to end at $11.02.