The University of Murcia has planned a telephone numbering change will affect all extensions and has had to be taken because the previous range, 968-36, was saturated.
The change was made so as to retain the current extensions in all cases, so that will survive the last four digits of each phone number.
Basically, you change the current prefix 96-839 96-836 and 86-888 by the numbers, which are already operational.
During a transition period may be used both current and new numbers.
Source: Universidad de Murcia