Online retailer Amazon is now using Microsoft's Windows Live search to power search results for its Alexa toolbar and A9 search engine.

Previously, the company used Google's search engine to power those results.

According to sources close to Amazon, A9 last week added Windows Live search results in addition to those powered by Google. But yesterday, the contracts to use Google search for both A9 and Alexa expired and Alexa began using results powered by Windows Live. Now Windows Live is the sole search engine powering results for both services.

An Amazon spokesman declined to comment on whether the company will renew its contracts with Google for A9 and Alexa.

Microsoft has been working diligently over the past two years to improve its search engine to compete with Google. Eventually, Windows Live Search, which is currently in beta, will replace its MSN Search product.