Amazon MP3 hasn't come anywhere close to toppling iTunes in the digital music market, though it has carved out a small but solid second place spot for itself (and gotten the attention of Apple). Now Amazon MP3 may be making new plans to boost its market share. TechCrunch reports that Amazon MP3 is gearing up for some kind of relaunch and has embarked on a hiring spree.

From TechCrunch:

We’re hearing from one source that Amazon is aiming for a major Q1 relaunch of the MP3 Store’s APIs and web services. They’re asking partners that are building out or planning to launch Amazon MP3 integrations to hold off until this new release is baked, we’ve heard.

Amazon MP3 also tweeted a job page yesterday highlighting more than a dozen open positions. Many of them are software development jobs in San Francisco.

According to the last batch of figures from NPD Group, Amazon's share of the digital-music download retail market grew by four percentage points to reach 12 percent in the first quarter of 2010. Apple's iTunes remained dominant — though flat — at 70 percent.

Apple has apparently taken note of Amazon's progress.

Billboard reported in March that iTunes representatives were urging music labels not to participate in an Amazon MP3 "Daily Deal" promotion giving exclusive access to new albums before their official release date.

The New York Times reported in May that the Justice Department had launched an inquiry into Apple's digital music market tactics, including its dealings with the music labels over Amazon's Daily Deal promotion.

Follow my updates on Twitter.