LOC and credit rating question

[JohnDoe]

I have a LOC with a 0 bal that I would like to close so that I can open a new LOC with a different firm. I will get a better rate and a few extra perks. Will this have an adverse effect on my credit rating?

Also, if I take the larger LOC, 100k instead of 50k, I will get another half point reduction in rate. The are no costs to me to open this new line. Should I do it? I don't plan on tapping it in the foreseeable future.

Thanks.
JD