SINGAPORE, Aug 15 (Reuters) - Singapore's Straits Times Index fell more than 3 percent in early afternoon trade on Wednesday as bank stocks extended earlier losses, mirroring falling shares on Wall Street and lower Asian markets.

By 0409 GMT, the key index was down 104.22 points, or 3.1 percent, at 3,282,37 points. The benchmark index, at its lowest in four and a half months, is still up 10 percent for the year.

Shares in Jakarta fell 4.4 percent, while the Philippine stock index declined 4.1 percent. Malaysia's stock market fell 2.2 percent.

Banks led losses, with DBS Group Holdings , Southeast Asia's biggest lender, down 3.3 percent. United Overseas Bank , Singapore's second-largest bank, fell 2.8 percent and Oversea-Chinese Banking Corp. slid 4 percent.

Index heavyweight Singapore Telecommunications lost 2.9 percent.

U.S. stocks skidded on Tuesday on fresh signs that global credit markets were seizing up, while a lower profit forecast from Wal-Mart Stores Inc. renewed worries about consumer spending.