[BioC] Is there an R package to export genotype data to PED /MAP files?

[Javier Pérez Florido]

Dear list,
Is there a way to convert genotype Affy data files (chp files - Affy SNP 
6.0 arrays) to PED / MAP files (used by PLINK) by means of some R package?

Thanks for your time,
All the best,
Javier