Never heard of it. Doesn't mean it doesn't exist. Doubt that it would be factory since the P89 replaced it years ago. Get a P91. It is a P85/P89/P90 in .40 cal. Looks just like the others. Another mfg. disc. Apparently, Ruger introduced it before the .40 really caught on. When the .40 caught on, they made the P94 in .40 cal (P944) and did not reintroduce the P91. I don't know why. The P89/P90/P91 series has the more traditional military look and they still make the P89 and P90. The P94, P93, P95, P97 have the more futuristic look. I have owned them, put prefer the P89/P90/P91 look and those are the 3 I am keeping along with my Sigs.
If you do want a Ruger .40 cal, I will sell you a stainless P944 with 2 mags, night sights, and Hogue grips for $425 or it's matching 9mm for the same price, or the pair for $825. Again, notice they both have night sights already installed.
If that is not what you want, go to
www.gunsamerica.com and search for a P91. You can get one for about $325 to $350, without night sights or the Hogue grips.