MediaPost reports that Yahoo is closer to permanently outsourcing its search advertising to Google after a two-week test of the system went well, according to The Wall Street Journal Thursday.

The site said that a search-ad deal could theoretically complicate Microsoft's efforts to acquire Yahoo, but is unlikely to completely derail its plan in the end.

This follows a related report from Reuters saying that new industry data showed Yahoo may have started gaining share in the Web search ad market against Google, even as Google's share of search audience inched up.

What's interesting about this particular aspect of the Web portal saga is that Google used to power Yahoo searches. Back in 2000, Yahoo signed an agreement with Google for this express purpose, only to abandon it four years later in place of their own search engine algorithm. Now that Google has run away with the search market, and is in the process of running away with the search ad market, Yahoo is once again looking to partner with the Mountain View-based company.

(Image credit: NYT)