President Bush announced Friday his nomination of defeated Sen. Chic Hecht, R-Nev., to be ambassador to the Bahamas and his selections of new ambassadors to Switzerland and Malaysia.

Besides Hecht, who lost his bid for a second term despite intensive campaigning on his behalf last year by President Reagan, Bush said he intended to nominate Paul Matthews Cleveland as ambassador to Malaysia and Joseph Gildenhorn to succeed Philip Winn as ambassador to Switzerland.If confirmed by the Senate, Cleveland would succeed John Cameron Monjo, who previously served as ambassador to New Zealand and Western Samoa.

Gildenhorn is a lawyer and real estate developer who has served with the general counsel's office of the Securities and Exchange Commission.

Hecht, from Las Vegas, where gambling is legal, as it is in the Bahamas, was defeated in November by Nevada's Democratic Gov. Richard Bryan.