When Andrew Charlesworth took over as sales and marketing director of Wolford London three years ago, he knew as much about hosiery as any male. "Apart from the odd Christmas purchase for my wife," said the 36-year-old Brit, "I knew nothing about hosiery."Sales at Wolford-the Dom Perignon of hosiery, at $22 for a pair of stockings-have climbed an average of 30% annually since Mr. Charlesworth joined the 50-year-old company. Since early 1994, Wolford's U. K. sales have doubled while retail sales for the total U.K. hosiery market have shrunk to $640 million from $800 million. Mr. Charlesworth's performance is even more impressive considering that Wolford spends only about $250,000 a year on advertising, all of which isdone in-house."In our international success story, Andrew is somebody who created a higher growth than all the other [markets]," said Fritz Humer, chairman and CEO of Wolford, based on Lake Con stance in Bregenz, Austria. "He's one of the leaders at Wolford." The U.K. has even overtaken Austria to become Wolford's third-largest market after Germany and France.Mr. Charlesworth attributes his success to plain common sense : He decided to inject some sexy fun in a brand that was regarded as well-made, but slightly fuddy-duddy.A background in selling cosmetics proved invaluable for Mr. Charlesworth because of the similarities between upmarket hosiery and fragrances. The imagery, product quality, store spacing and trade people are alike, he said."First, we had to inform and convince the trade of the potential of the product," he explained. "We restructured the retail informat ion so figures were coming in weekly instead of quarterly; we needed communication to strengthen the brand within the store."After improving relations with the trade, Mr. Charlesworth then focused on the consumer. To enhance Wolfo rd's image of exclusivity and to ensure that consumers always saw the complete range of products, Mr. Charlesworth slashed the number of Wolford outlets to 375 from 850. He negotiated more space in department stores and top indepen dent fashion stores and supervised the opening of three Wolford boutiques. Seventeen more are slated to open in the U.K. by the end of 1998."Consumer workshops" invite small groups of consumers-both loyal and prospective-to depar tment stores to listen to a Wolford manager espouse the brand's virtues. The concept has been adopted in Germany, France, Switzerland and Italy.To launch its new line of support and shaping products, Wolford's marketing team relied on a steamy ad campaign shot by renowned photographer Helmut Newton. The sexy series of photos show women wearing only black sheer pantyhose, stiletto pumps and black bras.Mr. Charlesworth placed the erotic photos in the windows o f London department store Fenwick for a month. Store managers in Germany, Austria and Switzerland snatched up the ads for their windows after witnessing the sales surge.Mr. Charlesworth is hoping to stir up a similar response with January's launch of Wolford's "swimbody" range. The line of skintight, seamless swimwear will use images from underwater photgrapher Howard Schatz.