The U.S. Treasury Department has failed to win agreements to get struggling borrowers’ home- equity debt reworked, among the biggest roadblocks to reducing foreclosures that may reach a record 3 million this year. None of the lenders holding a combined $1.05 trillion of the debt has signed contracts requiring participation in the second-mortgage modification plan announced eight months ago. The largest banks remain “committed” to joining, Meg Reilly, a department spokeswoman, said in an e-mail.