Abstract: An orderly succession of first tobacco articles (4), each defined by a double cigarette portion, is fed, with a first pitch (P1), to a first portion (S1) of a path (B) along a filter assembly machine (5); as they travel along the first portion, the first articles (4) are cut into respective pairs of portions (13, 14), and the portions in each pair are spaced axially and then fed along a second portion (S2) of the path (B); as they travel along the second portion, the portion (13, 14) in each pair are separated by the interposition of a double filter (21) to form a succession of second articles (29), each defined by the relative pair of portions (13, 14) and by the relative interposed double filter (21); a respective strip (33) being applied, by rolling, to each second article (29) to connect the pair of portions (13, 14) and the double filter (21) and form a third article (40) defined by a double cigarette; and the first articles (4) being subjected to a pitch reduction to assume, along the first portion (S1)