NEW YORK (Reuters) -JPMorgan Chase ( JPM ) boosted its outlook for investment banking revenue, forecasting a jump of 25% to 30% in the second quarter fueled by capital markets, a top executive said on Wednesday.

In May, the bank had predicted investment banking revenue would rise by a mid-teens percentage in the second quarter.

"Capital markets continues to be extremely robust and the overall franchise has improved," said Troy Rohrbaugh, co-CEO of JPMorgan's ( JPM ) commercial and investment bank.

Trading revenue is expected to improve slightly, exceeding the bank's earlier estimate for a percentage gain in the mid-single digits.

In the first quarter, JPMorgan's ( JPM ) trading revenue fell 5% to $8 billion, with revenue from fixed income, currency and commodities dropping 7%, while equities was flat.

Meanwhile, investment banking revenue gained 27% to $2 billion in the first quarter, driven by higher fees for debt and stock underwriting.

JPMorgan's ( JPM ) board has identified Rohrbaugh as a potential candidate to succeed CEO Jamie Dimon, who is expected to step down in less than five years.

The other contenders include Jennifer Piepszak, Co-CEO of commercial and investment banking, Marianne Lake, CEO of consumer and community banking, and Mary Erdoes, CEO of asset and wealth management.