Moody's downgrade of the U.S. sovereign credit rating late Friday appeared to have a modest impact on corporate bond market activity on Monday, as spreads widened slightly and new bond sales started the week softer than expected.

Moody’s Ratings downgraded the United States’ debt on Friday, stripping the country of its last perfect credit rating. The move could rattle financial markets and push up interest rates.Video above: Best money moves to make right now in a volatile ...

Moody's downgrade of the U.S. sovereign credit rating has elicited mixed responses among Republicans in Congress, with some questioning the motive behind the change and others depicting it as a warning that lawmakers should heed as they wrestle with a sweeping tax and budget bill.