Amazon may be planning some major changes for its MP3 store, which competes with Apple’s iTunes store. The online retailer is apparently aiming to relaunch the MP3 store’s API (which allows developers to build software that communicates with the store) and web services in the first quarter of 2011, a source tells the technology blog TechCrunch.

The source goes on to say that Amazon is currently advising partners who are building MP3 store integration into their own software to wait until the revamp is more concrete.

Amazon is also looking to hire many more employees for the MP3 store’s team. The popular AmazonMp3 Twitter account recently tweeted a job page that contains a few digital music-related positions in Seattle and San Francisco (via Amazon’s A2Z subsidiary). Among the more lofty positions that need filling, Amazon is looking for a Senior Product Manager, as well as two Senior Vendor Managers.

Amazon has a long way to go before it can catch up to Apple’s iTunes store, which is the top music retailer in the US with 26.7 percent of total sales. The online retailer accounts for 7.1 percent of US music sales, but most of that is from physical CD sales. Its MP3 store accounts for a tiny 1.3 percent of US sales.

Launched in 2003, Apple’s iTunes Store  basically shaped the digital music market as we know it and also has several years of consumer exposure ahead of Amazon’s MP3 store, which debuted in 2007. While a snazzier interface and more functionality may help to attract some buyers to Amazon’s MP3 store, its biggest hope for success right now is with its partnership with Google. Amazon’s MP3 store app comes pre-installed on all Android phones, and Google recently showed off some killer media integration at its I/O conference — including over-the-air purchases, and the possibility of a web-based iTunes competitor.