The global financial services firm has also lowered its growth projection for financial year 2016-17 to 7.6 per cent from 8.3 per cent earlier.
India's GDP growth rate slipped to 7 per cent in the April-June quarter of 2015-16, from 7.5 per cent in the preceding quarter.
The downward revision in growth projection comes despite lower oil prices which were expected to provide a boost to Indian growth.
"Weaker external demand prospects and slow progress on balance sheet repair leads us to curtail our growth forecast in spite of cuts in UBS' Brent oil price projections to an average of USD 57.5 in calendar 2016 (from USD 70)," UBS said in a research note.
The brokerage said that a combination of below potential growth and balance sheet repair will keep inflation lower than the RBI's targets.
RBI, which has lowered the benchmark rate by a combined 75 basis points so far this year in three instalments, will hold its next bi-monthly monetary policy meet on September 29.