For Portuguese readers:
http://oglobo.globo.com/pais/mat/200.../285929322.asp
The article indicates the Legacy was at FL370, still under Brasilia ATC, while the 738 had requested and been cleared by Manaus ATC to climb from FL350 to 390.
An article in another newspaper quotes the president of Infraero suggesting the most likely scenario as that of the Legacy's winglet shearing hydraulic/electric lines in the 738's horizontal stabilizer.