Title: Measurements of Rb at sqrt(s) >= 192 GeV

The preliminary measurements of 
R_b = sigma(e+e- -> bb)/sigma(e+e- -> qq) 
at centre-of-mass  energies of 192 GeV, 196 GeV, 200 GeV
and 202 GeV are presented.
High energy events, with an effective centre-of-mass energy 
sqrt{sprime/s}>0.85, are selected.
The single-tag method is used, exploiting the relatively large decay length
of b-quarks. 


Parallel session #PA 5
Plenary session #Pl 6