New numbers from the comScore Networks research firm show Microsoft Bing rising to 10.3 percent of the U.S. search market in November, according to a JP Morgan report cited by Silicon Alley Insider. It's the highest result for Microsoft's search engine in more than two years, according to our collection of historical comScore data.

However, Microsoft appears to be taking market share not from its nemesis Google but from its partner-in-waiting, Yahoo. Google's U.S. market share rose slightly, reaching 65.6 percent from 65.4 percent the month before, according to the report. Yahoo dropped to 17.5 percent from 18 percent.

Under an agreement struck earlier this year, Microsoft will assume responsibility for the underlying technology for both the Yahoo and Bing search engines. Microsoft has said the arrangement will give it more critical mass to compete effectively against Google. The companies said Dec. 4 that they finalized terms of the agreement, and they're still hoping to complete the deal in the early part of next year, pending regulatory approval.

In July, when the deal was announced, Yahoo had 19.3 percent U.S. market share, according to comScore, while Bing had 8.9 percent.

Update: I mentioned our collection of comScore U.S. search data, which is just our log of the numbers issued each month in comScore's news releases. The trends are pretty interesting, and informative, when viewed over a longer period of time. Here's what they look like.