The Magpies have targeted the 26-year-old Frenchman, who has only a year left on his contract at Fulham, as one of their major signings this summer.
However, having believed they had seen off competition from Everton and West Ham with Manchester City also reported to be monitoring his situation, they have discovered Boro are interested in the former France Under-21 international.
Newcastle, who were confident of landing the player for around £3.5million, will hope to be able to offer Malbranque the possibility of UEFA Cup football through the Intertoto Cup next season, something last season's beaten finalists cannot.
But new Boro manager Gareth Southgate has inherited a squad packed with young and emerging talent from Steve McClaren and, having already secured a verbal agreement with Germany defender Robert Huth, will hope to persuade the midfielder that his future lies on Teesside rather than Tyneside.
For Magpies' boss Glenn Roeder, the retirement of Alan Shearer and Michael Chopra's departure for Cardiff means strikers will be his main priority but his search will extend further.
Sporting Life.