I am writing in response to the advertisement for:
(phrase) This phrase explains what the purpose of the email or letter is. After 'Dear Sir/Madam' or 'Dear Mr/Mrs/Miss' (See the Email Essentials Exercise for an explanation of the difference), this phrase should always be the first thing that is written.
It is used when it is the first contact/letter/email about the job/position. It is always followed by the full title of the job/position (. 'the position of a marketing manager') and sometimes by the location of the job.
'I am writing in response to the advertisement for the position of an IT consultant in your Leeds office'.
In Spanish: "me dirijo a usted en respuesta al anuncio para" .