Amsterdam's red light district has been a major draw for decades. But a deal reached Thursday will cut the number of prostitute display windows by a third. It's all part of Holland's attempt to clean up its image. Mention that you've been to Amsterdam, and you'll likely to get a knowing smirk. While the Netherlands' capital is home to beautiful canals, stunning art and lovely 17th-century residences, the city is equally known internationally for its pot-purveying coffee shops and its vibrant red light district, complete with prostitutes posing in windows to lure the punters. But the red light part of that equation may soon be changing. A deal reached on Thursday between the city and a real estate magnate named "Fat" Charlie Geerts is set to eliminate 51 of the iconic display windows. Amsterdam Mayor Job Cohen says that, while prostitution remains legal, the sex-worker spectacles are a magnet for miscreants. "What we want is to get rid of the underlying criminality," Cohen told Dutch television on Thursday. "We're very busy making a development plan and we hope to have that ready by the end of the year." The plan affects about a third of the display windows in Amsterdam's famous Wallen district and the city hopes the move will take a bite out of trafficking and pimping -- problems that plague the sex industry in Amsterdam and indeed across Europe. But De Rode Draad (The Red Thread), an advocacy and support group for Holland's prostitutes, says that the move misses the target completely and disadvantages the sex workers themselves. "By closing down the windows, you take a lot of work away from prostitutes who work independently," Sietske Altink, a deputy spokeswoman for De Rode Draad says. "It doesn't make sense to penalize the women when you want to go after the owners. Closing down the windows doesn't help the women." Women rent out the display windows at a cost of €100 for a half day to show off their wares. While returns vary depending on the time of day, prostitutes can rake in several hundred euros during an evening shift, Altink says. Limiting the number of windows will merely drive the rental costs up with little added protection, she says. Amsterdam has for years been trying to stem criminality in the city center -- driven, officials say, by marijuana sales and prostitution. In 2002, the city passed a law requiring businesses to submit detailed records in order to get their licenses renewed. Indeed, the city is forcing Geerts to close his windows under the provisions of that law. Geerts filed a suit last year in an attempt to stay in the shop window business. But he lost and is now selling 18 buildings to a public housing corporation for €25 million. Mayor Cohen on Thursday hinted that there may be more restrictions to come. "The legalization of prostitution did not bring about what many had hoped," he said in the television interview. "We are still faced with distressing situations in which women are being exploited. It is high time for a thorough evaluation of the prostitution act." De Rode Draad, though, says the government needs to go after the criminals themselves rather than the prostitution industry. "We have already held our own protests to try to drive the pimps away," Altink says. "There's not much we can do except express our anger with the government and ask the local government to help us operate our own places." Her plea will likely go unheard. Holland has for years been trying to clean up its slightly seedy image. In recent years, hundreds of coffee shops have been forced out of business and Dutch police have cracked down on illegal marijuana cultivation in the country. Thursday's deal will likely force many prostitutes out of the Amsterdam city center and into other red light districts on the edge of the city. Cohen says he is not interested in ridding the Wallen district of all sex workers, as the trade is part of the neighborhood's identity and tradition. Limiting the supply of premises will, however, likely make window shopping a bit more expensive. "The windows are very popular," Altink says. "The prices will surely go up."