Washington Mutual this week announced a new “covered bond” program that will give the top-tier mortgage originator – and MBS issuer – an alternative to traditional mortgage securitization and borrowing from the Federal Home Loan Bank System. The $26 billion program, which is being promoted in various European locales during the next two weeks, is unique in that it permits the covered asset pool of mortgages to stay on the company’s balance sheets, according to officials at Standard & Poor’s, which gave a preliminary triple-A rating to the bonds...