The pair - both 21 - are represented by agent Spencer Downey and are also the subject of interest from Championship sides Bolton, Huddersfield and Doncaster.
Downey said of the situation: "Newcastle have offered the lads contract extensions but the talks are on-going. There is still an agreement to be reached on matters like the lengths of the contracts so we will just have to wait and see what happens.
"Nothing has been decided yet and there is interest from other clubs. But Newcastle have been impressed by the way Conor and Paul have been treated during their time in Scotland and have agreed that if they do sign for Saints permanently, they will not ask for the compensation fee they are entitled to.
"Instead they will just ask for a sell-on clause to be inserted in their contracts that will see them take a share of any future profit."
Newton, who like Dummett played a significant role in helping the club win the Scottish Communities League Cup triumph, added: "I haven't accepted the deal from Newcastle yet, we're still talking but I know that other clubs have been on to my agent.
"I owe a lot to St Mirren. It's been a great season for me but nothing has been put down on paper about a permanent move here.
"But it would be an option I'd consider as I've loved my time up here. It's still early for me. I would like to test myself down south at some point in my career but I've only been playing first-team football for the past four months so I'm not nave enough to think I'm just going to walk into the side at Newcastle.
"So the next few months are crucial for my development. But I would love to make it at Newcastle and get a chance to play in those black and white stripes. It's what every lad from the city dreams of. Right now, though, I will just bide my time."