AMSTERDAM (Reuters) - Dutch telecoms firm KPN (>> KPN KON) said on Tuesday that the offer by America Movil (>> America Movil SAB de CV), the telecoms group controlled by Mexican tycoon Carlos Slim, substantially undervalued the company.

America Movil on Monday offered to buy a stake of up to 28 percent for as much as 3.2 billion euros ($4.2 billion), or 8 euros per share.

"KPN is of the opinion that 8 euro per ordinary KPN share substantially undervalues the company. KPN will seek further clarification as to América Móvil's intentions," KPN said in a statement.

"In the meantime, KPN will explore all strategic options," it added.

(Reporting by Gilbert Kreijger; Writing by Sara Webb)

Stocks treated in this article : America Movil SAB de CV, KPN KON