The baht ended three days of losses as international investors increased holdings of Thailand's debt amidst optimism the economy is improving.
The baht rose 0.1 per cent to 28.90 per dollar as of 9:41 am Thursday in Bangkok after reaching a one-week low of 28.99 earlier in the day, according to data compiled by Bloomberg.
The currency touched 28.56 on April 22 and April 19, the strongest level since a devaluation in July 1997 that sparked the Asian financial crisis.
Five-year government bonds rose. Global funds bought $2.2 billion more sovereign debt than they sold this month through Wednesday, taking this year's net purchases to $12 billion, Thai Bond Market Association data show.
The Bank of Thailand raised its 2013 growth forecast on April 12 to 5.1 per cent from its January estimate of 4.9 per cent.
The central bank is concerned about the baht's advance to a 16-year high earlier this month, assistant governor Chantavarn Sucharitakul said Wednesday.
"Inflows in bonds continue and the baht is still under pressure to appreciate," said Kozo Hasegawa, a currency trader at Sumitomo Mitsui Banking Corp in Bangkok. "But there is concern about intervention and also some demand to buy dollars, slowing movements in the baht for now."