Microsoft Corp.'s (MSFT) revamped search engine, dubbed "Bing," got off to a good start in its first week since launch, helping to boost the software giant's Internet-search market share to 11.1% from 9.1%, according to research group comScore Inc. (SCOR).

"So far it appears that the lifts in searcher penetration and engagement have held relatively steady throughout the five-day period," said Mike Hurt, comScore senior vice president, on Tuesday. "It appears it is off to a good start."

Hurt added that the ultimate success of Bing will depend on the extent to which it generates more trial through its extensive launch campaign and whether it retains those trial users.

Bing is a central element of Microsoft's effort to drive new revenue growth by winning a greater share of the Internet advertising market. The Redmond, Wash., software company currently has long been stuck with less than 10% of the Internet search market. Mountain View, Calif.-based Google Inc. (GOOG), which accounts for about 64% of Internet searches, continues to gain share in the largest and most lucrative area of Internet advertising.

ComScore said Microsoft sites increased their average daily penetration among U.S. searchers from 13.8% during the period of May 26-30 to 15.5% during the period of June 2-6, 2009, an indication that the search engine is reaching more people than before.

Microsoft's share of search-result pages in the U.S., a proxy for overall search intensity, increased to 11.1% from 9.1% during the same time frame.

Shares in Microsoft were recently up 0.2% at $22.08. Google shares were off 1.2% at $433.72.

-By Scott Morrison, Dow Jones Newswires; 415-765-6118; scott.morrison@dowjones.com