Ratings agency Fitch has assigned a BB+ rating on $US1.5 billion worth of unsecured notes to be issued by Fortescue Metals Group.
Fitch said the rating is unchanged from the expected rating it placed on a $US800 million note issue earlier this month.
The BB+ rating has been placed on $US600 million of senior unsecured notes due in February 2016, and $US900 million in unsecured notes due in February 2018.
Fitch said its final rating had not changed because of the increase in size of the final issue.
The bond issue will be used to fund Fortescue's expansion activities and for other general purposes.
The outlook on Fortescue's BB+ long-term foreign currency issuer default rating and senior unsecured rating is stable, Fitch said.