Noble Corporation plans to replace its underperforming Noble Muravlenko rig for Petrobras in Brazil with Noble Phoenix, which is deployed with Royal Dutch Shell in Brunei.

Noble Phoenix will be shifted to Brazil later in 2011 to address reliability issues, subject to Shell releasing Phoenix.

Noble will also take a $40m charge for the cancellation of a Muravlenko upgrade scheduled for 2013.

Phoenix will earn the same as Muravlenko once they are swapped.

Noble has also signed a letter of intent for a five-year, six-month contract for a newly built deepwater rig with a Shell subsidiary.