* Dollar index slips back from previous day's highs

* Focus on Fed Chair Yellen's speech on Friday

(Updates prices, adds comments)

By Masayuki Kitano

SINGAPORE, Aug 23 (Reuters) - Most Asian currencies rose on Tuesday but gains were limited as investors awaited a speech by Federal Reserve Chair Janet Yellen for hints on the possible timing of a U.S. interest rate hike.

Asian currencies regained some footing as the dollar retreated broadly, with the South Korean won rising 1.0 percent and pulling away from a 3-1/2 week low set on Monday.

Firmness in South Korean equities helped lend support to the won, said Wu Mingze, FX trader of global payments for financial services provider INTL FCStone in Singapore.

South Korean shares rose 0.4 percent and foreign investors turned buyers before the closing bell.

Investors are now waiting for fresh hints on the outlook for U.S. interest rates from Fed Chair Janet Yellen, who is due to deliver a speech on Friday at the Fed's annual conference in Jackson Hole, Wyoming.

Yellen will be speaking in the wake of a series of upbeat comments by Fed policymakers including New York Fed President William Dudley, who said last Tuesday that a rate hike was "possible" as soon as September.

Such comments are probably laying the groundwork for Yellen's speech at Jackson Hole, said Philip Wee, senior currency economist at DBS Bank.

"This year, markets have gotten used to the Fed pause leading to risk rallies and a lower U.S. dollar. The Fed probably thinks this has gone on too long and too far," Wee said.

Against a basket of six major currencies, the dollar slipped 0.3 percent to 94.281 , down from Monday's intraday high of 94.958.



THAI BAHT

The Thai baht edged higher, with traders citing inflows into local bonds and dollar-selling by local exporters.

The baht held firm even after comments from Thailand's central bank governor, who said a rapid rise in the baht was not good for the country's economic recovery although it was not causing exports to decline.

He added that the baht was not stronger than regional currencies. The baht has risen about 4 percent against the dollar this year.

Change on the day at 0717 GMT Currency Latest bid Previous Pct

day Move Japan yen 100.02 100.33 +0.31 Sing dlr 1.3472 1.3508 +0.27 Taiwan dlr 31.694 31.820 +0.40 Korean won 1114.97 1126.50 +1.03 Baht 34.58 34.67 +0.26 Peso 46.510 46.580 +0.15 Rupiah 13222 13210 -0.09 Rupee 67.06 67.19 +0.20 Ringgit 4.0200 4.0200 -0.00 Yuan 6.6396 6.6525 +0.19

Change so far in 2016 Currency Latest bid End prev Pct

year Move Japan yen 100.02 120.30 +20.28 Sing dlr 1.3472 1.4177 +5.23 Taiwan dlr 31.694 33.066 +4.33 Korean won 1114.97 1172.50 +5.16 Baht 34.58 36.00 +4.11 Peso 46.51 47.06 +1.18 Rupiah 13222 13785 +4.26 Rupee 67.06 66.15 -1.35 Ringgit 4.0200 4.2935 +6.80 Yuan 6.6396 6.4936 -2.20

(Additional reporting by IFR Markets' Catherine Tan; Editing by Richard Borsuk) ((masayuki.kitano@thomsonreuters.com; +65-6417-4682; Reuters Messaging: masayuki.kitano.thomsonreuters.com@reuters.net))