El Segundo-based DirecTV Group Inc. said Thursday that it will buy back 15 million common shares this month, at a cost of $257.3 million, from its former parent company’s pension fund.

The nation’s largest satellite-television provider will pay $17.15 for each of the shares it is buying from General Motors Corp.’s Special Hourly Employees Pension Trust and Special Salaried Employees Pension Trust. The purchase is to be completed by June 7, DirectTV said in a statement.

DirecTV is a former General Motors subsidiary that was known as Hughes Electronics Corp. until 2004. General Motors transferred the shares to its pension funds in December 2003 when it divested Hughes in a spinoff and sold shares of Hughes stock to News Corp., now the company’s largest holder.

After this month’s transaction, DirecTV said it will have repurchased about 160.1 million of its shares for about $2.56 billion as part of a $3 billion buyback program. In February, the company announced plans to buy back 100 million shares from the General Motors benefit plans for $15.50 each.

DirecTV shares were downgraded to “neutral” from “buy” by analyst Thomas Eagan at Oppenheimer & Co., with a price target of $19 per share. The stock gained 24 percent this year, and was up 0.46 percent to $17.64 in late trading Thursday.