Even the best Spanish-speakers are sometimes stumped when it comes to ending a business letter. Business letters call for an ending that is sometimes cheery, sometimes serious, and always professional. Some people want to end an English business letter in Spanish as a sign of respect to the recipient's culture, but they aren't sure which word to use and don't want it to sound awkward and disjointed. There are many Spanish words that are appropriate for ending a letter, depending on the voice and style of the letter.
In terms of punctuation, Spanish business letters should be closed in the same manner of English letters. The ending address should be followed with a comma, with your signature immediately below.
The most common and most respectful ending to Spanish business letters is "atentamente." This word is similar to the English "kindly." For a more formal letter closing, write, "le saluda atentamente," or "les saluda atentamente" for a letter addressed to more than one person.
When writing a more casual business letter, close the correspondence with "cordialmente," which is similar to the Spanish "sincerely." "Un cordial saludo" is a similar closing that is appropriate for business letters.
"A la espera de sus prontas noticias," is an ending that directly translates to "I hope to hear from you soon." This closing doesn't particularly evoke a sense of your respect towards the recipient, but is appropriate for most business letters.