There is no information on this single about the year of release, but several internet sources put this single in the year 1977. It makes sense: at the height of the disco era, pretty young girls were coupled to cheesy disco anthems or disco covers of wellknown songs. In this case, it's the latter: a version of a song originally recorded by Abba.
'Nina pretty ballerina' was written by Benny Andersson and Bjorn Ulvaeus and recorded by the Swedish pop group in 1973. Released as a single in France and Austria only, it reached number 8 in Austria. This cover version was less successful: as far as I could find out, it didn't chart. However, the girls did make an appearance in the German music show Musikladen...
My collection: 7" single no. 5064
Found: Record fair, Utrecht, April 9, 2011
Cost: 1 euro
Tracks: 'Nina, pretty ballerina' / 'Sweet night of love'