* Asian stock markets : https://tmsnrt.rs/2zpUAr4

* Asian shares tad lower; South Korea stocks mildly positive

* Analysts cite high valuations, upcoming risk events

* Oil prices rise, gold falters

By Swati Pandey

SYDNEY, Aug 24 (Reuters) - Asian shares started cautiously on Monday on jitters over heady valuations though sentiment was underpinned by coronavirus hopes after the U.S. Food & Drug Administration (FDA) authorised the use of blood plasma from recovered patients as a treatment option.

The announcement from the U.S. FDA of a so-called “emergency use authorization” came on the eve of the Republican National Convention, where Donald Trump will be nominated to lead his party for four more years.

MSCI's broadest index of Asia-Pacific shares outside of Japan was last down 0.04%, but not too far from a six-month high touched last week.

Australian shares were flat while Japan's Nikkei was reversed early losses to be last up 0.07%.

South Korea's KOSPI, which has been on a slippery slope since hitting a more than two-year peak earlier this month, was mildly positive.

E-Mini futures for the S&P500 added 0.2%.

Analysts urged caution with Wall Street indexes already at record highs even as the world economy struggled to recover from the coronavirus pandemic.

"Outside of new all-time highs on tech-driven indices, most markets and equity sectors are stalling given an array of low-intensity concerns around global growth," said JPMorgan cross asset analyst John Normand.

"With risks rising somewhat and September a full month for policy, the end of summer is a good time to cross-check valuations and to consider both threats and opportunities."

Normand pointed to talks of a U.S. fiscal package, Fed's upcoming policy review next month and the ramping up of the U.S. election campaign as risk events over coming weeks.

Looming large over this week was a keenly anticipated address by Federal Reserve Chair Jerome Powell at the Kansas City Fed Jackson Hole symposium, where he will talk on the Fed’s monetary policy framework review.

"This takes on even more significance after the market’s evident disappointment last week," said Ray Attrill, head of forex strategy at Melbourne-based National Australia Bank.

The Fed's July meeting minutes last week barely made a mention of its policy outlook while "failing to give succour to expectations" that its September meeting would reveal a formal commitment to new outcome-based' forward guidance, Attrill added.

In currencies, the dollar nudged up on the safe haven Japanese yen to 105.90.