Can anyone suggest specific street names or locations for concentrations of art galleries to visit in Paris(especially interested in sculpture)?

There is a concentration of galleries around the rue Louise-Weiss (13th arrondissement)

Rue Keller, rue Bonaparte, rue des Saints-Pères, etc.

Try the Louvre de Antiquaires , across from the Louvre..lots of galleries

http://www.antikaparis.com/pages/louvre.htm

Many galleries around Place des Vosges, including my favourite one : Art Symbol.

Just a bit of interest:
This summers's blockbuster exhibition will be 'from Cezanne to Picasso', which opens on June 19 at the Musee` d'Orsay (www.museeorsay.fr)and is devoted to the art dealer Ambroise Vollard, who collected the work of Gauguin, Renoir, Degas & Matisse, among others. Until then, get along to the just-opened retrospective at the Bibliotheque Nationale celebrating the photographer Eugene Atget, whose sepia portraits of the city at the turn of the 20th century have a bewitching stillness (www.bnffr.fr) until July.
Of the museums opened over the past couple of years, the 250million Euro Musee du Quai Branly (www.quaibranly.fr) is by far the grandest. Squatting beside the Eiffel Tower, Jean Nouvel's Chinese barge-like building is hard to love, but theres no doubting the power of it's displays of ethnic treasures, garnered from colonial days -
extract from Nigel Tisdall's article on Paris.

There are several on avenue Matignon and even more on rue du Faubourg Saint-Honoré.

Artcurial (www.artcurial.fr) is always worth a visit.

Thanks to you all for the helpful tips - we'll be checking these out while in Paris this May!