Burlington Stores Inc. is to announce that it is moving from the three floors it occupies at its current location to a two-story space at Ninth Street and Market, according to PREIT and Macerich. Burlington said in a separate release that it would open in its new space this fall. A spokeswoman did not know when the store would cease operating in its 11th Street location, or how its new location would compare in size with the current one.