Foreign investors bottom-fishing in Asia's beleaguered equity markets are beginning to hedge their currency exposure to reduce the risk of foreign exchange losses.

''Hedging the currency risk of equity investments has only recently taken hold,'' said a fund manager in Singapore. Previously, foreign exchange hedging - which can cost a high premium - was not widely practiced. Some reports blame equity investors' lack of currency hedging for causing the (Thai) baht's fall last July to snowball into a regionwide currency and economic crisis.''Before the crisis, the volatility in the currency market was low, with most currencies either pegged or moving in a relatively tight range,'' the fund manager added.

But since July, many of the region's currencies have seen massive erosion in their values versus the U.S. dollar. The Indonesian rupiah, for instance, is now worth about 25 percent of its July 1997 value in U.S. dollar terms.

Equity investors' sales of the Asian currency proceeds when they liquidated their stock portfolios also reportedly exacerbated panicked U.S. dollar buying and worsened the Asia currency meltdown last year.

Apart from their sharp depreciations, Asian currencies also have become very volatile, moving as much as over 10 percent in a day against the dollar.

Consequently, recent stock purchases have been accompanied by foreign exchange hedging activities.

''There is a bit of support (Monday) on the bid side of the Asian foreign exchange swaps from foreigners buying stocks and then hedging the positions outright three-to-six months forward,'' said an analyst in Singapore.

Southeast Asian equity markets had soared Monday, led by foreign buying with the key indexes in Thailand, the Philippines and Singapore registering double-digit percentage gains.

Hedging also makes sense for many equity investors because they were dealt two heavy blows when Asia was suffering the worst of its recent crisis.

Not only did regional currencies sharply depreciate, stock prices also plunged throughout regional markets, said the Singapore analyst.

For instance, Singapore's key stock index ended Monday at 1432.99, while the Singapore dollar was trading at 1.7155 U.S. dollars, compared with levels of 2271.88 and 1.4050, respectively, on Jan. 20, 1997.

However, the fund manager said her company felt that covering currency exposure was not that necessary, since the firm's policy, in general, was to buy and hold stocks for at least three years.

But the firm was considering hedging some of the shorter term investments if the costs were not too excessive, she added.

As Asian currency interest rates are higher than U.S. rates, investors hedging their currency exposure will have to pay a premium, which can sometimes be very expensive.