Maurice Hadida's collection of rare stamps includes an 1852 envelope mailed from Tangier, and the first-ever English stamp sent from Morocco to Britain, in 1860. Mr. Hadida's album, philatelists agree, is one of the most original and impressive in the world.

But to win a top prize at the world stamp-collecting championship in London in May, Mr. Hadida has to stick it to two formidable competitors: a collector of Icelandic naval-mail stamps and an expert on Siberian Railway postage. Letters sent from the North Pole or remote whaling stations are particularly in vogue at the moment.

'It won't be easy,' said the 58-year-old insurance-company executive as he flicked through a pile of brown faded envelopes at an outdoor stamp market here in Paris one Sunday recently. 'Finding a rare envelope is like wooing a beautiful lady,' continued the Moroccan-born Frenchman. 'The harder the chase, the better it feels in the end.'

Mr. Hadida is one of the world's top philatelists -- an eclectic group of stamp-collecting fanatics whose thousands of members include business executives, politicians and dignitaries such as French President Nicolas Sarkozy and Queen Elizabeth II of England.

Despite the number of enthusiasts, the art of collecting postal material is on the wane. The pastime, which started in the mid-19th century and was coined philatelie by a Frenchman in 1864 -- is suffering as young people increasingly turn to the Internet for communication and distraction. 'Young people no longer need to turn to stamps to discover the world,' says Joseph Wolff, the president of the International Federation of Philately. 'They just turn on their computer.'

At its highest reaches, the hobby is increasinglycompetitive. Only about 2,000 people in the world have collections that are good enough to be eligible for internationalcompetitions, according to the Universal Postal Union, the organization that coordinates postal policies around the world. Applicants can submit material in different categories including postal history; aerophilately, the study of airmail, and maximaphily, the study of postcards. But to qualify, collectors must have a track record of victories in local and national contests -- a considerableinvestment of time, collectors say. It's also expensive: One of the most valuable stamps in the world currently is an orange, 1847 one-penny stamp from the island of Mauritius. It is known in philatelic circles as the Mona Lisa of stamps; only two exist and each has an estimated value of $4 million, according to Paris stamp broker Pascal Behr.

To prepare for the London competition, which is one of the most prestigious, Mr. Hadida has spent the past few months scouring the Internet, reading philatelic magazines and talking with stamp dealers. Even the hours spent gazing at and arranging his collection are worthwhile, he says. 'When I see a stamp, I am touched by its beauty.'

The first stamp ever, called a 'Penny Black,' was made in the U.K. in 1840, and stamp collecting began shortlythereafter. As the pastime took off around the world, clubs sprang up in several countries, and the first international stamp exhibition was held in 1881, according to the International Federation of Philately.

France, which started mass producing stamps in 1849, has one of the richest philatelic cultures in the world. One of the oldest stamp books was made in Paris in 1862. For the next century, France was a philately powerhouse, with many Frenchmen winninginternational stamp-collecting competitions, according to Jean-Francois Logette, the head of the philately service at the Universal Postal Union.

But in the 1970s, when several big French stamp collectors died, their families put up their albums for auction, and France lost much of its stamp heritage, Mr. Logette says.

According to the Federation Francaise des Associations Philateliques, which groups all the philatelic associations in France, stamp-club membership has fallen to 40,000 from 60,000 in the past decade.

In 2007, Mr. Sarkozy tried to re-invigorate the hobby by ordering the French Post Office to make nicer stamps to attract new collectors.

Mr. Hadida fell in love with stamps while growing up in southern France, and he joined a local philatelic association in his early twenties. There, a mentor urged him to focus on Morocco. Few philatelists had paid much attention to stamps from the former French colony.

Mr. Hadida refined his search even further: His envelopes follow the life span of the French post office of Tangier, which opened in 1852 and closed late in 1924.

Over the past 31 years, Mr. Hadida has collected several hundred envelopes, though he says he has never actually counted how many pieces he has. Among his prized stamps is the first envelope sent by Moroccan airmail in 1911. His stamp from 1852 is believed to be on the second-oldest franked envelope ever sent by a French post office in Morocco.

As he prepares for the London contest, however, Mr. Hadida, who has won other prizes, has a hurdle to overcome: Collecting postal material from old French colonies isn't fashionable. The stamp craze of the moment centers on adventure, including expeditions to the poles and mail sent from whaling stations or space stations. Mr. Logette says the next big philatelic trend will probably be postal material depicting climate change. 'It could interest young people,' he says.

Recently, Mr. Hadida, who won't talk about how much money he has spent on stamps, has been redoubling his efforts. He bought his 1860 stamp -- which is on the first envelope sent from Morocco to Britain with an English stamp -- at an auction in Barcelona. A photograph of the envelope has since been featured on a new stamp created by the Gibraltar Post Office.

He is also continuing his 30-year quest for a letter bearing a postmark from the small town of Mequinez, in the north of Morocco. He bid twice for it at auction, but was beaten.

'If I told Maurice I had a nice Moroccan stamp, he would run here naked if he had to,' says Mr. Behr, the stamp broker in Paris.

'You never know where a good piece will turn up,' Mr. Hadida said while standing in the rain at the stamp market. 'It's like looking for gold.'