Sales of corporate bonds in the U.S. fell this week and relative yields narrowed as political wrangling in Washington deterred borrowers.

International Lease Finance Corp., the commercial aircraft unit of insurer American International Group Inc., and Burlington Northern Santa Fe led issuance of about $25 billion, down from $35.2 billion last week, according to data compiled by Bloomberg. Sales this year total $307 billion, below $344.9 billion sold in the similar period 2012.

Issuance declined as the House of Representatives passed a plan to avoid a shutdown and preserve new spending cuts, while the Senate will consider a measure next week to fund the government through September. Borrowers are facing "issuance fatigue" after selling a record $1.47 trillion last year, according to Edward Marrinan at RBS Securities.