The National Gallery of Canada is installing a massive bronze spider by its front doors this week – and at a cost of $3.2 million, it's the gallery's most expensive purchase ever.

The sculpture, which carries 26 white marble eggs in its underbelly, will loom over the gallery's plaza, standing 9.25 metres tall and weighing 6,000 kilograms.

Called Maman, it is the last of six spiders cast by renowned Franco-American artist Louise Bourgeois as a tribute to her mother. It was created in 1999 and cast in 2003. Bourgeois was born in France in 1911 and has been working as an artist for nearly 70 years. She immigrated to the United States in 1938.

"Maman is a tremendous example of contemporary sculpture, one of the most important that has been produced in recent years and absolutely a major piece by a major artist and very fitting for the National Gallery" said gallery curator David Franklin.

"We are so lucky … it's a fabulous work of art and once people walk through it, it will be a fabulous experience and we should be grateful we have it here," said Penny Cousineau-Levine, art professor and chair of the University of Ottawa's visual arts department.

To purchase the huge arachnid, gallery officials used more than one-third of the museum's annual budget for acquisitions.

The three museums to have bought other casts of Maman are the Guggenheim Museum External link in Bilbao, Spain, the Mori Art Museum in Tokyo and the Samsung Museum of Modern Art in Seoul, South Korea. One is also on long-term loan to the Hermitage in St. Petersburg, Russia, and one is on display in Havana, Cuba.

Maman's $3.2-million price tag could raise a few eyebrows. Controversy swirled around past contemporary art acquisitions and exhibits, notably the purchase of U.S. artist Barnett Newman's Voice of Fire, the imposing, striped abstract painting the gallery purchased in March 1990 for $1.76 million, and Montreal artist Jana Sterbak's Vanitas, better known as the 50-pound, "meat dress" of flank steak that the gallery displayed in 1991.

Rather than being concerned about gallery-goers turning into Miss Muffets, Franklin says the giant spider is already doing what it's supposed to do – inspire people to talk about art.

"The very elegant structure of the spider will certainly enhance the entrance and hopefully draw people to the entrance who maybe have not come to the National Gallery before, but who will be fascinated by this piece," he said.

Maman joins several other Bourgeois sculptures in the gallery's collection. The 93-year-old artist – whose work is featured in institutions such as the British Museum, the Metropolitan Museum of Art in New York and Florence's Uffizi Gallery – is considered among the world's most important sculptors living today and will be celebrated with a retrospective at the Tate Modern in 2007.

On May 29, the gallery will unveil its other recent, big purchase: Reclining Male Nude, a 16th-century drawing by Pontormo.External link While the 25 x 38 cm drawing cost $3 million – almost as much as Maman – gallery officials don't expect it to generate nearly the same public interest or controversy.