Linking out to other sites is a ranking signal that Google takes into account (read Google’s Matt Cutts statement quoted below). You will find this factor tagged as positive, negative or neutral, depending on when the statements were made, and which Google employee mentioned it. However, Matt’s statement clearly mentions that Google looks at what sites you link out to:
“Q: Okay, but doesn’t this encourage me to link out less? Should I turn off comments on my blog?
A: I wouldn’t recommend closing comments in an attempt to “hoard” your PageRank. In the same way that Google trusts sites less when they link to spammy sites or bad neighborhoods, parts of our system encourage links to good sites.” source
Did you know that there’s another algorithm that measures the number of links going out from a page? It’s called CheiRank and is the opposite of PageRank, which measures the number of incoming links to the page.