The plans are yet to be made official but have been widely reported in the Spanish media, and the alleged increase would see Telefonica hit a top speed of 300Mbps before this summer.
The operator is yet to comment on the reports, but it is thought that the increase will affect both ADSL and fibre networks, with ADSL customers to be automatically migrated to fibre broadband as soon as it becomes available in their areas.
Telefonica looks to be reducing its interest in the UK market with the confirmed sale of its UK mobile unit O2 to Hutchison, but it now appears to be increasing efforts in its home market and earlier this year, acquired a stake in Spanish digital services firm Indra.
Telefonica holds a monopoly over last mile connectivity in Spain, similar to BT in the UK, and late last year, the Spanish regulator Comisión Nacional de los Mercados y la Competencia (CNMC) proposed legislation whereby Telefonica would have to provide competitors with access to its fibre network at a regulated wholesale price.