ROME, Dec 12 (Reuters) - A small centre-right party that supported Matteo Renzi's ruling coalition has threatened not to back his successor Paolo Gentiloni as prime minister, potentially depriving him of a majority in parliament.
Gentiloni was named to take over from Renzi, who resigned last week, and is presenting his chosen cabinet to President Sergio Mattarella.
However, Denis Verdini, head of the Liberal-Popular Alliance for Autonomies (ALA), issued a statement saying his group would not back the new government in parliament because it was not sufficiently represented in Gentiloni's cabinet team.
Parliament is highly fragmented and it was not immediately clear whether Gentiloni could win a necessary confidence vote in the upper house Senate later this week without Verdini's support. (Reporting By Gavin Jones)