I think a good translation would be
"even though a country may suffer a slowdown in the rythm of its growth while converging with developed countries, this, by no means, implies an economic stagnation."
Key words:
Si bien= aunque= no obstante= all introduce concesive clauses
growth rate = tasa de crecimiento
money exchange rate = tasa de cambio (de divisas)
converger = converge. In the text it is implied that developing countries will reach developed countries and at a certain point they will "converge", that is, they growth or wealthy will be equal.