Shell Programming and Scripting

I have a file that I want to split in 2 (with Bourne shell sh) preferably. The file consists of groups of lines separated by newline. The file can vary in length, so I need to check number of groups of text. Here's an example

====EXAMPLE START====
#fruit banana
#color yellow
#surface smooth
size 20cm

#fruit apple
#color green
#surface smooth
size 7cm

#fruit grape
#color green
#surface smooth
size 2cm
====EXAMPLE STOP====

I want to split the file in 2 equal pieces in the sense that there will be equal amount of "fruits" (or groups of texts) in each. But the file should only be split just before a "#fruit" tag so that no fruit-text is split in the middle.
By equal pieces I mean that if the file has data for 4 fruits it should split it so that I will have 2 files with 2 fruits in both. 3 fruits should split to 2+1. 7 fruits should split to 4+3 a.s.f. The example above would result in 2 files:
======
File1:
#fruit banana
#color yellow
#surface smooth
size 20cm

#fruit apple
#color green
#surface smooth
size 7cm
======
File2:
#fruit grape
#color green
#surface smooth
size 2cm
======

I can easily find number of fruits by doing:
i=`grep "# fruit" fruitfile | wc -l`

...and then find after which group I should split:

j=`expr $i / 2`

But from here I am more unsure.

Borge