In a statement, Opera said: "Google will be the default search partner for the mobile browsers: Opera Mobile and Opera Mini."
Opera Software's Opera Mini browser, a mobile browser is due for formal unveiling next month.
"It's of great importance to have a search partner on board before the announcement," said Christian Jebsen, Opera's COO, said in a telephone interview Thursday. "We've been exploring different ways to make the product user-friendly. If you press the 9 (button), it takes you right to Google for searching."
Jebsen said users of Opera Mini can still use the more established way of accessing a search engine, simply by calling up book-marked search engines. He noted that Opera is comfortable with Google as a partner because it has had a good working relationship with the search colossus for several years.
While Opera has not been charging users for its Mini browser, Jebsen said the firm has been exploring revenue-generating options and the arrangement with Google should eventually bear fruit in that regard.
Opera Software supplies two major browsers for mobile and wireless devices. Earlier this month, Opera quietly released a preview of its Opera Mini. Early user reaction has generally been complementary. Complete details will be reported at next month's unveiling of Opera Mini.
The Mini version operates on WAP-equipped cell phones, while the more robust Opera Mobile version is generally offered as an add-on to mobile and wireless devices for a small user fee.
Opera has been battling rumors of an acquisition by Google. Earlier this week, Opera put down more rumors of an acquisition by Microsoft by saying it was not for sale.