Northrop Grumman Corp.’s debt was upgraded Friday after it refinanced $1.2 billion of outstanding loans using a new $2 billion loan at a lower interest rate, according to a Securities and Exchange Commission filing.

Northrop’s $5.2 billion in long-term credit and unsecured debt were upgraded to BBB+ from BBB by Standards & Poor’s Ratings Services. The debt was removed from CreditWatch because of Northrop’s improved earnings and debt reduction.

The new loan secured from JPMorgan Chase & Co. refinanced $1.2 billion of Northrop’s debt and will save the El Segundo-based defense contractor up to $2 million a year.