Yahoo! Sports reported earlier Tuesday that the Nets have offered the job to Marks and are awaiting his decision.
Marks was one of three finalists for the Nets' GM vacancy, along with former two-time NBA Executive of the Year Bryan Colangelo and Denver Nuggets assistant GM Arturas Karnisovas, sources told ESPN last week.
ESPN reported over the weekend that Marks was gaining steam as a Nets target in part because of the franchise's admiration for Marks' mentor, Spurs general manager R.C. Buford.
Sources say Marks, 40, emerged during the interview process because of his experience in the NBA as a player, coach and executive. A 6-foot-11 native of New Zealand, Marks played in 230 career games with seven teams in 11 seasons, averaging 2.8 points and 2.2 rebounds.
He has served as an assistant coach and executive in San Antonio and worked as GM of San Antonio's D-League team, the Austin Toros, before rising to become Buford's assistant.
Buford was the fantasy target for Nets owner Mikhail Prokhorov and his Russian advisors, but Brooklyn never had a realistic chance at luring him away from the Spurs and Gregg Popovich.
Buford, though, remains close with Prokhorov's trusted Russian confidant, Sergey Kushchenko, who sits on the team's GM search committee alongside Dmitry Razumov, Brett Yormark and Irina Pavlova.
Assuming Marks accepts the Nets job, San Antonio assistant coach Ettore Messina is sure to be mentioned as an eventual candidate for the Nets' head coaching job, thanks not only to his time with the Spurs but also a stint coaching CSKA Moscow in Russia when it was owned by Prokhorov.
King was reassigned within the Nets organization on Jan. 10.