Appearing at AllThingsD’s DX conference yesterday, Napster co-founder and Spotify investor Sean Parker suggested Apple may have tried to block Spotify’s introduction into the U.S. market.

“There was some indication that was happening,” said Parker. “We’re in constant re-negotiating so you hear things. People send you emails.” He remained cryptic, only going as far as saying, “Apple was threatened by what we were doing.”

Founded by Daniel Ek in Sweden in October 2008, Spotify began negotiating with U.S. labels in late 2009. However, a domestic launch didn’t occur until July 2011.

Worldwide, the service currently has 18 million users, drawn in by the ease of its playlist creation and sharing (enhanced by Facebook integration). It wouldn’t come as a surprise if Apple seemed wary of Spotify—iTunes, in comparison, seems out of touch, with Ping failing to provide a suitable sharing option. 

[via Tech Crunch