NEW YORK (Reuters) - As JPMorgan Chase investors puzzle over who will eventually replace Jamie Dimon as CEO, two of the contenders say they are more focused on winning market share and developing the bank's future leaders.

"The competitive landscape is remarkably intense," Jennifer Piepszak, co-CEO of the commercial and investment bank at JPMorgan ( JPM ), told Reuters in a joint interview with co-CEO Troy Rohrbaugh.

He concurred, citing challengers from all sides.

"We have big global competitors going toe to toe with us," Rohrbaugh said. "We have regional competitors on the banking side and also non-bank competitors in e-trading, lending, private credit."

Under the two executives, revenue from JPMorgan's ( JPM ) newly merged commercial and investment banking unit rose to a record $35.5 billion in the first half. In particular, investment banking revenue grew 46% to $2.5 billion in the second quarter versus a sluggish period a year earlier.

The pipeline for investment banking deals is promising for the third quarter, although it is too soon to tell how the market will evolve, Rohrbaugh said.

"Debt capital markets has done well," Rohrbaugh said. "While the equity capital markets are opening up and there are more advisory assignments, the overall market is still not that incredibly robust with lots of IPOs or mergers."

While the looming Nov. 5 U.S. presidential election could spur some clients to finalize business before the outcome is settled, it has not led to a flurry of activity so far.

"Everybody is very interested in talking about the election," and discussing scenarios for markets and business decisions, but those conversations have not spurred major actions yet, Rohrbaugh said.

The co-CEOs expressed guarded optimism for JPMorgan's ( JPM ) trading business in the second half of the year.

After losing some market share in fixed income, currencies and commodities (FICC) and equity capital markets, the bank is trying to close gaps with rivals by deepening client relationships and serving more middle-market companies, executives told investors in May.

The bank will also have to fend off competition from senior JPMorgan ( JPM ) alumni who have joined rivals in recent months.

Viswas Raghavan took over Citigroup's banking division in June after holding a similar role at JPMorgan ( JPM ). Fernando Rivas joined Wells Fargo as co-CEO of corporate and investment banking. And Carsten Woehrn was appointed Goldman Sachs' co-head of mergers and acquisitions in Europe, the Middle East and Africa (EMEA).

Despite JPMorgan's ( JPM ) position atop the U.S. banking industry, Piepszak and Rohrbaugh said they remained vigilant for competitive threats. They warned against complacency at a time when rivals have particular insight into JPMorgan's ( JPM ) inner workings.

"If you dropped in on a business review at this company, you would never guess that you were inside JPMorgan ( JPM )," Piepszak said.

The executives are also focused on building the next generations of talent in their unit.

Dimon this year told investors that his timeline for stepping down was less than five years.

The other potential CEO candidates are Marianne Lake, CEO of consumer and community banking, and Mary Erdoes, who leads asset and wealth management.