(Adds details, background from paragraph 2 onwards) Aug 22...

(Adds details, background from paragraph 2 onwards)

Aug 22 (Reuters) - Australia's Whitehaven Coal (WHC) reported an 87% drop in its full-year profit on Thursday, as coal prices cooled off from their historic highs and on lower production at its flagship Narrabri mine.

Global thermal coal prices retreated from their peaks hit at the onset of Russia's invasion of Ukraine as trade flows adjusted to Russian sanctions, energy security concerns diminished and supply outpaced demand.

Australia's largest independent coal miner reported net profit after tax attributable of A$355 million ($239.48 million) for the year ended June 30, compared with A$2.67 billion a year earlier. The earnings missed the Visible Alpha consensus estimate of A$767.3 million.

The Sydney-headquartered miner declared a final dividend of 13 Australian cents per share, lower than the 42 Australian cents a year ago.

The miner also said on Thursday it would sell a 30% stake in its Blackwater coal mine, which it acquired from BHP Group (BHP) last year, to Japan's Nippon Steel 5401.T and JFE Steel Corp for an aggregate $1.08 billion.

($1 = 1.4824 Australian dollars)