Authorization Header is missing in Http request using WCF

I am accessing a web service using WCF. Using WSHttpBinding, Security mode is set Transport (https) and client credential type is Basic. When I try to access the service using the proxy, getting an 401 unauthorized exception.

Here is the Binding

var binding = new WSHttpBinding()
        {
            UseDefaultWebProxy = true,
            Security =
            {
                Mode = SecurityMode.Transport,
                Transport =
                {
                    ClientCredentialType = HttpClientCredentialType.Basic,
                },
            }
        };

Here is the service call

var client = new InternetClient(binding, new EndpointAddress("httpsurl"));

        client.ClientCredentials.UserName.UserName = "username";
        client.ClientCredentials.UserName.Password = "password";
        client.ProcessMessage("somevalue");

When looked into Http headers using Http Analyzer CONNECT HEADER

(Request-Line):CONNECT somehost.com:443 HTTP/1.1
Host:somehost.com
Proxy-Connection:Keep-Alive

POST HEADER

(Request-Line):POST /Company/1.0 HTTP/1.1
Content-Type:application/soap+xml; charset=utf-8
VsDebuggerCausalityData:uIDPo+voStemjalOv5LtRotFQ7UAAAAAUKLJpa755k6oRwto14BnuE2PDtYKxr9LhfqXFSOo8pEACQAA
Host:somehost.com
Content-Length:898
Expect:100-continue
Connection:Keep-Alive

If you see the header Authorization header is missing

Now my question is why WCF call missing the Authorization header? Am I missing something? . Please ask if you need more information