Which ending sentence is the best to use in a formal letter from a company to a client?

We trust that we have informed you satisfactorily.

We hope to have been of service.

Any more suggestions?

It really depends on the content of the letter. Your ending needs to be relevant.

'Please do not hesitate to contact us if you have any further queries' is probably the most standard ending I can think of, if you want something very generic.
And remember...Buy Spacely Sprockets!
Site Hint: Check out our list of pronunciation videos.
Marvin A.And remember...Buy Spacely Sprockets!
Thanks, but I just need a formal ending sentence without anything commercial in it.
I'm Dutch, but we do receive English e-mails quite often.
Then I would recommend: "We hope to have been of service."
Marvin A.Then I would recommend: "We hope to have been of service."
Is that really the most commonly used ending sentence? Google only gives about 3,000 results worldwide!
Teachers: We supply a list of EFL job vacancies
 nona the brit's reply was promoted to an answer.