Swiss drugmaker Roche again extends $4.3 billion Spark offer until December 16

ZURICH (Reuters) - Swiss drugmaker Roche <ROG.S> again extended its offer for shares of gene therapy specialist Spark Therapeutics <ONCE.O> to Dec. 16 as a regulatory review of the $4.3 billion (3.35 billion pounds) transaction drags on.

All terms and conditions of Roche's offer remain unchanged, it said in a statement on Monday.

(Reporting by John Miller; editing by Thomas Seythal)