BY SPENCER E. ANTE AND NICK WINGFIELD
One third of its way into a five-year deal to make its Internet search and advertising services the default option on Verizon Wireless cellphones, Microsoft Corp. is still struggling to make headway in a market that continues to be dominated by Google Inc.
The arrangement with the largest U.S. wireless carrier, struck in early 2009, was aimed at vaulting Microsoft into a competitive position on the mobile Internet. But the deal gave Verizon the right to use Google’s search engine on phones powered by Google’s Android software, according to people familiar with the matter.
So far, on seven of its …