The pass-through certificates are rated AA- by Fitch, a rating agency.

Northwest Airlines $500 million of pass-through certificates in three parts.

The pass-through certificates are offered through a Discover Card Trust 1991-A.

Smith's Food and Drug Centers 1994-1 Trust, $155 million of pass-through certificates.

The pass-through certificates carry a 9.35 percent coupon and have an expected final payment date of Oct. 15, 1995.

The underwriting group gave the pass-through certificates an 8.55 percent coupon and priced them at 99.94 to yield 8.65 percent.

The 9 percent credit card account pass-through certificates carry a final maturity date of Sept. 15, 1993.

MBS are commonly referred to as "pass-through" certificates because the principal and interest of the underlying loans is "passed through" to investors.

The yield spread to the investor on the 23-year pass-through certificates is about 141.5 basis points more than the yield of a 30-year Treasury bond.

The obligations, offered in six parts, are backed by 8 1/2 percent Federal National Mortgage Association pass-through certificates.