The Spaniard, as reported by Cyclingnews at the Tour de France, will make the move from Tinkoff, who are folding at the end of this season, joining established Grand Tour leader Mollema at Trek-Segafredo.
The Dutchman has been at Trek since the start of 2015 and has finished seventh and 11th in the last two editions of the Tour de France, with his best result of sixth coming in 2013. This year he was on course for the podium but crashed out of contention in stage 18's downpour.
However, the arrival of Contador, whose palmares includes two Tour de France titles along with three at the Vuelta a Espana and two at the Giro d'Italia, signals a disruption to the pecking order.
With both riders set to make the Tour de France their primary objective of the 2017 season, the age-old leadership issue is bound to rear its head, but Contador insisted the partnership will not lead to any tensions.
"There's no problem," he said in an interview with Dutch newspaper De Telegraaf. "We have plenty of races ahead of the Tour to get used to each other and I am confident that we will both discover the benefits of working together.
"I am convinced that we can strengthen each other, that we can form a strong partnership. He can probably learn something from my experience just as he can give me different insights too."
Contador knows what Mollema is like to race against and was impressed by what he saw at the Tour this year.
"Bauke was very strong during the last Tour. On Mont Ventoux, he was the only one who could bridge the gap to Chris Froome and Richie Porte. In the subsequent time trial, he confirmed his talents as a classification rider. It is unfortunate that he fell on the way to Saint -Gervais-Mont-Blanc.
"I see him as a very consistent rider who is willing to go on the attack. I look forward to working with him."