(Reuters) -Rio Tinto reported a largely flat half-year underlying earnings growth on Wednesday as slightly weaker iron prices were partially offset by stable shipments.

Iron ore prices tumbled about 15% in the first half as top consumer China continues to deal with a years-long property crisis that has put a lid on demand, along with below-expected stimulus from Beijing.

Average realised prices for Rio's flagship Pilbara iron ore slipped marginally to $97.30 per wet metric ton (wmt) in the first half from $98.60 per wmt a year earlier.

The world's largest iron ore producer reported underlying earnings of $5.8 billion for the six months ended June 30, compared with $5.7 billion a year ago and Visible Alpha consensus of $5.80 billion.

The miner declared an interim dividend of $1.77 per share, in-line with last year's payout.

(Reporting by Rishav Chatterjee and Adwitiya Srivastava in Bengaluru; Editing by Sriraj Kalluvila)