Yelp is heading down under to Australia via a partnership with the directory company Sensis where it will integrate Sensis’ local business listing data into its site. In turn, Sensis’ local sales force will sell Yelp.com.au to Australian SMBs.

Neither company has revealed the financial details of the partnership, but Sensis CEO Bruce Akhurst did discuss the idea behind the new alliance. “Small businesses are looking for customers to come through their door, and the whole phenomenon of Yelp and what they’ve been doing is a rich source of leads and customers for small businesses,” Akhurst said in an article from The Australian.

Just last week, we reported on Yelp’s sizable growth. Since March of last year, reviews on the site have doubled. It now boasts 20 million user-generated reviews. Yelp was founded in 2004 by two former PayPal execs. Cofounder Jeremy Stoppelman said the Sensis partnership was the first time Yelp had chosen to team up with a directory service business for an international launch.

Yelp’s previous international launches include Canada, the United Kingdom, Ireland, France, Austria, Germany, Spain and the Netherlands.

The new partners expect that Yelp.com.au will go live by the end of this year with Sensis’ Yellow Pages sales reps offering Yelp advertising options to customers in 2012. This deal represents the continued evolution of Sensis in terms of how it views competitors. In the not too distant past, it’s fair to say Sensis would have been loathe to consider a partnership with Yelp. Today, it seems to take the view that it’s better to work with than against potential competitors.