A hydrosilylation process is used to prepare a polyorganosiloxane having clustered functional groups at the polyorganosiloxane chain terminals. The ingredients used in the process include a) a polyorganosiloxane having an average of at least 2 aliphatically unsaturated organic groups per molecule, b) a polyorganohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule and at least 4 silicon bonded hydrogen atoms for each aliphatically unsaturated organic group in ingredient a), c) a reactive species having, per molecule at least 1 aliphatically unsaturated organic group and 1 or more curable groups; and d) a hydrosilylation catalyst. The resulting clustered functional polyorganosiloxane is useful in a curable silicone composition for electronics applications.