General Motors Corp. should absorb the pension obligations of Delphi Corp.’s salaried retirees, Sen. Charles E. Schumer said in a letter to GM’s chief executive officer, Fritz Henderson.

Delphi salaried retirees are opposing GM’s decision to allow their pension benefits to default to the federal Pension Benefit Guaranty Corp. That shift could reduce the pension payments the retirees receive by up to 70 percent, according to the Delphi Salaried Retiree Association. About 15,000 retirees would be affected, the group said.

A federal bankruptcy court judge on July 23 could approve the plan to transfer the pension obligations to the PBGC. Delphi is moving toward emerging from Chapter 11 bankruptcy.

Schumer in his Monday letter to Henderson praised GM for agreeing to absorb the pension obligations of Delphi’s hourly workers, but said the salaried employees deserve the same solution.

“The salaried employees worked side by side with the hourly employees for decades and, therefore, this divergent treatment strikes me as [being] unfair,” he wrote.

GM has agreed to take back five Delphi operations, including its Lockport plant. GM spun off Delphi a decade ago.

Last month, 22 members of Congress, including Reps. Chris Lee, R-Clarence, Brian Higgins, D-Buffalo and Eric Massa, D-Corning, signed a letter sent to Treasury Secretary Timothy Geithner, urging the federal government’s auto task force to release documents related to the decision to default the Delphi salaried retirees’ pensions to the PBGC.