no difference in search engines whatsoever, inlcuding the majority of extensions.
*however* once people find your site through a search engine, they may remember your domain name, but might type the .com extension as it is the most known and used in the world. You therefore lose some traffic to the .com owner.
If your site is well established, the amount of traffic lost is not significant.
when starting out however, it is best to start with a .com for these reasons and for brandability.
Still the other extensions are just as good for SEO