Convert cURL multi-line output to single, semi-colon-separated line

I'm using curl -s -I -L example.com | grep 'HTTP\|Location' to track re-directs of a given URL which gives multi-line output.

$ curl -s -I -L google.com | grep 'HTTP\|Location'
HTTP/1.1 301 Moved Permanently
Location: http://www.google.com/
HTTP/1.1 200 OK

I want to concatenate each line of the output and separate it with a semi-colon.

HTTP/1.1 301 Moved Permanently;Location: http://www.google.com/;HTTP/1.1 200 OK;

I've tried curl -s -I -L google.com | grep 'HTTP\|Location' | tr '\n' ';' > file but this only replaces \n with ; and doesn't concatenate the lines.

$ curl -s -I -L google.com | grep 'HTTP\|Location' | tr '\n' ';' > file    
$ cat file
HTTP/1.1 301 Moved Permanently;
Location: http://www.google.com/;
HTTP/1.1 200 OK;

Would be grateful for any ideas. Thanks.