To be honest, there aren't that many options with a better yield.
You are obviously comfortable taking quite significant risk with your investments as you have a lot of money in one company. Looking closer to home, the likes of Ensure Group, National Grid and Royal Dutch Shell all have dividends above 5% but there is no guarantee this will remain the case.
If you wanted to spread your risk a little more, you could consider a fund. I'm not a fan of bonds right now as rising interest rates could result in capital losses but if you wanted to put some money in this asset class, both the Henderson Strategic Bond and Jupiter Strategic Bond funds have yields above 5%.