Dimon hands power to JPMorgan CFO Marianne Lake

Marianne Lake, JP Morgan Chase's chief financial officer, has just been given a major career boost from one of Wall Street's most influential CEOs.

Lake was thrust into the spotlight Tuesday when JP Morgan Chase CEO Jamie Dimon announced that Lake could take his place in one of the company's most high-profile events: Its earnings calls with analysts.

"Before you all go I just want to tell you: One of these days I'm not going to come in on this call," Dimon said at the end of the banking giant's second-quarter earnings call.

Dimon, 59, who has never missed an earning conference call since named CEO of $250 billion bank in 2005 — even when being treated for throat cancer last year — explained that he's not lessening his role so much as putting Lake forward.

"I'm not doing it because I want to avoid it or don't like it," Dimon said of the quarterly earnings updates, which kick off at 7 a.m each quarter. "But Marianne ... (does) such a good job that I have become unnecessary to be on all of them."He also gave a nod chief of investor relations, Sarah Youngwood.

"It shows a lot of confidence (in Lake)," said Paul Miller, analyst at FBR Capital Research. "I think it shows that she has a lot of confidence and she has a lot of competence in explaining the business," Miller said.

Lake was promoted to CFO in early 2013 following the "London Whale" trading debacle in which a single trader cost the bank a whopping $6 billion. Since then, the U.K. native, who received a degree in physics from Reading University, has helped set expectations for capital requirements, expense reductions and other matters for investors and analysts.

Lake, 45, who was previously CFO of JPMorgan's Consumer & Community Banking unit, described to Marie Claire in 2013 her strong relationship with Dimon, known for his tough-talking ways.

"Our offices are right next door, and we're in and out of each other's offices multiple times a day," she told the magazine a few months after her promotion. "Every Friday night we try to sit down together and go over things, but it's not always necessary. We're usually on the same page."

"I think this is a sign that he feels more comfortable with his management team and that results should be less volatile ahead," said Mike Mayo of brokerage CLSA.

Still, Mayo criticized Dimon for his decision to begin bailing on quarterly earnings updates.

"It would be a mistake for him to not remain involved in the quarterly conference calls and to reduce the amount of access that he gives to investors," said Mayo, one of the top-known banking analysts on Wall Street. "People like to hear from Jamie Dimon so why reduce the level of access to the CEO? We are adamant that he should remain involved."

"That surprised me," added Shannon Stemm, an analyst with Edward Jones. "I think its unusual for a CEO not to join a quarterly earnings call."

Indeed, of all the large banks, only Goldman Sachs CEO LLoyd Blankfein regularly skips the company's quarterly calls.

JPMorgan Tuesday kicked off what is expected to be a ho-hum earnings seasons for banks, which are waiting for a rise in interest rates to boost earnings on loans.

The New York City bank said it earned $6.3 billion, or $1.54 per share in the three months ended in June. That's a rise of 5% over last year's second-quarter earnings of $5.98 billion, or $1.46.

The increase was due in good part to the bank's recent cost-cutting efforts, however, as revenue declined slightly, by 3.2% to $24.5 billion from $25.3 billion a year ago.

Wells Fargo, meanwhile, reported increased profit and revenue, but its $21.3 billion in quarterly revenues missed analysts' expectations for sales of $21.7 billion. Bank of America reports its quarterly earnings on Wednesday, followed by Citigroup and Goldman Sachs on Thursday.