Maierhofer's loan is due to expire on April 11 and will take in seven games, starting with Tuesday's Championship clash at Plymouth.
Since arriving from Rapid Vienna in a £1.8million move last summer, Maierhofer has made just two starts and seven substitute appearances.
He scored on his Premier League debut when coming off the bench at Blackburn but his most recent senior action was against Manchester United at Old Trafford in December.
Maierhofer slipped down the pecking order with Wolves boss Mick McCarthy using Kevin Doyle as his only striker and also having back-up from Sylvan Ebanks-Blake, Sam Vokes and Andy Keogh.
Wolves boss Mick McCarthy said: "This is a good move for Stefan and offers him the chance to enjoy some regular football."
Iwelumo had the opportunity to remain at City for a further month but the Scotland international has chosen to return to Wolves to fight for a first-team spot.
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