NTLM Authentication

I have a legacy service that I am trying to implement calls from within soapUI.  I have run fiddler while the application that generates the requests runs and have captured all of the information about the requests.  I am attempting to use a REST construct within soapUI as this isn't a soap service.  I'm assuming this should work.

Here is the basic structure of the request, i've removed servernames for security purposes and xx 'd out the authorization string for the most part.

POST https://www.testserver.com/Export/RequestXML.aspx HTTP/1.1
Accept: */*
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip, deflate
Content-Length: 94
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3; .NET4.0C; .NET4.0E)
Host: www.testserver.com
Accept-Language: en-us
Connection: Keep-Alive
Cache-Control: no-cache
Authorization: Negotiate TlRMTVxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx=

Body

<XML><STATUS><PARAMETERS companyid= "xx" getlookup="xxxxxxxx"/></STATUS></XML>

When I try to implement this in soapUI using NTLM it generates 'NTLM' rather than 'Negotiate' for the authorization header.  This seems to be the only part of the request that isn't matching what I see in fiddler.  Passing the exact authorization string as part of the header that is seen in fiddler also does not work.

Any tips for implementing negotiated NTLM requests?

Thank you