Aug 2 (Reuters) - Global miner Rio Tinto RIO.AX RIO.L on Wednesday reported its first-half profit more than doubled from a year earlier following a rebound in iron ore prices and announced an additional $1 billion share buyback.
Underlying earnings for the six months to June 30 rose to $3.94 billion from $1.56 billion a year earlier, missing Thomson Reuters I/B/E/S analysts' forecast of $4.19 billion.
Rio Tinto declared a half-year dividend of 110 cents a share, from 45 cents a share a year ago.