KUALA LUMPUR, May 14 (Reuters) - Malaysia's stock market fell 1.7 percent at the open of trade on Monday while its currency dropped 0.9 percent, in the first session since the stunning election defeat of the coalition that had ruled the country for six decades.

Markets had been closed since last Wednesday's election, which unexpectedly swept Mahathir Mohamad back to the office of prime minister, and traders had widely expected stock prices and the currency to drop.

The currency touched a four-month low of 3.9850 against the dollar in early Monday. (Reporting by Tom Westbrook; Editing by Sam Holmes)