Zany Brainy Inc. is buying rival toy chain Noodle Kidoodle Inc. in a $35-million deal that would unite the two largest retailers of specialty toys in the United States. The deal would create a 163-store chain under the Zany Brainy name selling a wide range of educational toys. Combined sales topped more than $370 million last year. Under the agreement, 1.23 Zany Brainy shares will be exchanged for each Noodle Kidoodle share. In Nasdaq trading, shares of Zany Brainy, based in King of Prussia, Pa., fell 50 cents to close at $3.78, while Syosset, N.Y.-based Noodle Kidoodle shares rose 25 cents to close at $4.50.