Spanish term
Brindis Aniversario: Los esperamos para brindar por nuestro Aniversario.
Oct 7, 2011 16:12: Evans (X) changed "Level" from "PRO" to "Non-PRO"
Non-PRO (3): Barbara Carrara, philgoddard, Evans (X)
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Proposed translations
Because your words matter
Native in: English (Variants: UK, US) 
Works in: Spanish to English
Anniversary Celebration: We hope to see you to celebrate our anniversary
Anniversary celebratio: Come and toast to the event with us
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Note added at 13 mins (2011-10-07 16:06:02 GMT)
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celebratioN!
*We hope you'll join us to celebrate our anniversary.
So, one option would be to mention the years up front. "10th Anniversary celebration: We hope you'll join us to celebrate out first 10 years in (the city, in XXX type of business)/ ten years of success in (city, sector, etc.).
Spain
Especialista de marketing
Native in: English
Works in: Spanish to English, Catalan to English
Anniversary event: We hope you will celebrate with us.
With the limited context, this is on the assumption that there is some kind of event being held.
Company anniversary event costs | AccountingWEB
www.accountingweb.co.uk/.../company-anniversary-event-costs...
We are considering holding a 25 year **anniversary event to celebrate the very successful growth of our company***. We intend to invite (with their respective ...
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Note added at 17 mins (2011-10-07 16:10:01 GMT)
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Or "WE HOPE YOU WILL JOIN THE CELEBRATION"
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Note added at 22 mins (2011-10-07 16:14:13 GMT)
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If you want something shorter and more punchy, you could say:
"ANNIVERSARY EVENT: COME JOIN THE CELEBRATION "
Depends on what kind of company it is.
Anniversary Meal: We look forward to seeing you at our anniversary meal.
How is the sender of the invitation going to get people to come unless there will be something for them to eat as well as drink?
La palabra justa/The right word
Native in: Spanish 
, English
Works in: Spanish to English, English to Spanish, Portuguese to Spanish, and 1 more.
Anniversary Celebration: Come raise a glass with us to our anniversary
"...good beer, and of course, live music. The event runs from 5-8, and we will play for a couple hours probably starting around 6. Come raise a glass with us! ..." (http://thewhiskeyfarm.com/blog)
"Come raise a glass with us @ Fife and Drum Pub! Mon-Fri from 4-6pm: $5 local beer & well drinks; with $10 weekly food specials. Open Patio!..." (http://twitter.com/.../status/93362917617045504)
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