I don't think Saruman would openly inform Sauron about the rings (if he knew who bore them). Now, Sauron might have gotten that info from Saruman, through the use of the palantir, but willingly, I don't think Saruman would tell Sauron.
Saruman wasn't only against the good side, he was also against Sauron. As Lal points, out he does some tricky double-dealing, and quite bold (and foolish) moves, of trying to take on both Sauron and the rest of Middle-earth.
Sauron and Saruman's relationship reminds me a lot of Hitler and Stalin.
In Stalin's case, both him and Hitler strove for total domination. They signed this pact, of sort of not really allies, but not attacking eachother either. They didn't combine forces, they simply signed this pact, saying they would leave eachother alone. Hitler, again was just using Stalin, he wanted to deal with the West first, and then he would turn on Stalin. Hitler, by getting Stalin to commit to this pact, thought he didn't have to worry about fighting on two fronts (which defeated Germany in WWI). It wasn't until Hitler made his mistake of ticking off Stalin, and foolishly believing he defeated the Western Front, which led to his downfall.
In Saruman and Sauron's case, again they weren't really allies, fighting with eachother. More of just agreed, that they both had the same enemies, and they would refrain from fighting eachother. Sauron very much like Hitler, just using Saruman for information, and not having to deal with Isengard as an enemy. He was dealing with Rivendell, and all, first, then probably planned to turn on Saruman. Again...When it comes down to it, they were both striving for total domination, and were at odds.
|