Bangkok  - Thailand's central bank on Monday intervened in the foreign exchange market to halt a rapid slide of the baht currency, officials said.

Suchada Gillakul, assistant to the Bank of Thailand's governor, said the intervention was deemed necessary after the baht dropped to 33.41 to the dollar Monday morning, its lowest rate in five months. It had closed Friday at 32.96.

"We will investigate whether foreign investors are speculating on the baht," she told reporters.

After the intervention, the baht traded at 33.22 to the dollar Monday afternoon.

Like most Asian currencies, the Thai baht has steadily appreciated against the dollar, gaining almost 20 per cent over the past two years before starting to weaken last month in the wake of rising inflation, growing political instability, declines on the stock market and slowing growth projections.

By midday Monday, the Stock Exchange of Thailand index had fallen 1.3 per cent largely in response to a dramatic fall on Wall Street Friday. (dpa)