NEW YORK ( TheStreet) -- Google ( GOOG) shares rose 0.3% to $583.40 in pre-market trading Thursday after the search giant announced a new social search tool called +1 -- or "plus one." The service lets users publicly recommend useful search results to friends. In other Google news, the company selected Kansas City, Kan. as the first city to receive its ultra-fast fiber optic broadband network. More than 1,100 communities expressed interest in becoming a part of the Google fast-fiber experiment to build and test broadband networks. Google proclaims its network will be more than 100 times faster than what Americans use today. Microsoft ( MSFT) filed a complaint Thursday with the European Commission against Google, alleging that the search giant is restricting competition via its Internet search results. The Commission has been investigating Google since last year when a number of small Internet companies lodged complaints. Shares of Microsoft were up 0.2% in pre-market trading Thursday. SK Telecom ( SKM) is considering bidding for bankrupt movie rental company Blockbuster ( BLOAQ), according to the Wall Street Journal. The South Korean company has been looking for ways to expand its business overseas. Nokia ( NOK) shares fell 0.7% to $8.56 after Standard & Poor's cut its debt rating for the first time to A- with a stable outlook from A. The firm cited Nokia's declining smartphone market share as the reason for the cut. --Written by Olivia Oran in New York. >To follow the writer on Twitter, go to http://twitter.com/Ozoran. >To submit a news tip, send an email to: firstname.lastname@example.org.