The telecommunications watchdog has also warned that E-Plus' frequency licenses stipulated that it remain independent.
Meanwhile, there may also be some resistance to Slim's ¿2.40-per-share offer for KPN itself. A foundation that essentially serves as a poison pill and was founded to safeguard KPN has said it's "concerned" about the bid.
The foundation, formally known as Stichting Preferente Aandelen B KPN, or Foundation Preference Shares B KPN, has an option to force KPN to issue it new shares equivalent to its current share capital minus one share.
KPN shares rose 2.4%, or ¿0.053, to ¿2.284 in early Amsterdam trading.--Written by Andrew Bulkeley