How do you no when you unlocked higher lvl missions? because Ive been doing lvl 3s for awhile now and still haven't unlocked lvl 4s.
Eelis Kiy [ Editor ]
Go to your Character Sheet then Standings and then scroll down to "Corporations".
Click on the show info button for a Corp and click on the "agents" tab.
You will now have a list of all available and not yet available agents for that particular NPC corporation. I'm pretty sure it also tells you how much Corp standing you need to access each agent not yet available to you.
Couple other points - If you stick to working for one corporation this will obviously help you open up new agents quicker (rather than splitting your mission time for different corps) and also the jump between level 3 and 4 missions in difficulty is considerable - don't be in a huge rush to get to level 4s unless you have people to do it with/are confident you have the skills in place to do them :)
I think the Connections skill can help you boost up your npc corp standings a bit also.