OSLO, April 29 (Reuters) - Norway's DNB, which recently launched a bid for rival Sbanken, reported a bigger-than-expected rise in first-quarter earnings on Thursday but said it was unlikely to reach its return on equity target for the year.

The banking group's net profit rose to 5.89 billion Norwegian crowns ($720.8 million) for the January-March period from 4.0 billion crowns a year ago, beating an average forecast of 4.93 billion crowns in a Refinitiv poll of analysts. ($1 = 8.1710 Norwegian crowns) (Reporting by Terje Solsvik, editing by Gwladys Fouche)