Prince Rainier, who put Monaco on the map by marrying Hollywood star Grace Kelly, has answered criticisms that modern skyscrapers have ruined the scenic beauty of his tiny Riviera principality.

In an interview published on Wednesday in the French daily Le Figaro, Rainier, 65, said he was not worried by critics who complained about the skyscrapers in Monaco's gambling resort of Monte Carlo.The monarch, who has reigned for nearly 40 years and reshaped Monaco's constitution, said: "It's true, I am nostalgic for the Monaco of the 1950s, when from the casino terraces you saw a postcard scene . . . but I believe there's no reason for regret.

"I have no passion for concrete, but space in the principality is at a premium, and there was no other possibility than to build up. Those who criticize us by saying that we are the Manhattan of the Mediterranean don't know Monaco well."

Rainier said: "In 40 years I believe I have succeeded in making the principality of Monaco a place to be taken seriously. It is no longer an operetta country. It is no longer a fiscal paradise. We have entered the 20th century on a straightforward footing."

Rainier, who began his reign in 1949, married Kelly in 1956.

She was killed in a car accident in 1982. The exploits of their children, particularly the two princesses Caroline and Stephanie, attract as much media attention in France as the British royal family does in Britain.

Rainier said he had not fixed a date for turning over power to his son, Prince Albert.