TORONTO -- The chief executive of Royal Bank of Canada (TSX:RY) says he's confident RBC can weather tough economic conditions, even as its loan books have begun to feel the impact of lower oil prices.

"What gives me confidence during this period of market and economic uncertainty is that RBC is diversified across different businesses, client segments and geographies, has strict risk and cost discipline, and is backed by a strong capital position," David McKay told analysts during a conference call Wednesday after the bank announced its third-quarter results.

RBC boosted its dividend as it reported a profit of $2.475 billion, up four per cent from a year ago. That amounted to $1.66 per share of net income.

On an adjusted basis, RBC's cash earnings were $1.68 per share, one cent above analyst estimates.

The bank says its quarterly dividend will be increased to 79 cents per share, up two cents per share.

However, the bank said it is beginning to be affected by the decline in the price of crude, which is now worth less than half of what it was in the summer of 2014 and recently traded at the lowest levels in years.

"As we expected, low oil prices are challenging for some of our clients," McKay said. "This quarter, we saw an uptick in impairments (impaired loans)."

The bank said total gross impaired loans rose more than 10 per cent over a three-month period to $2.38 billion as of July 31 -- a $234-million increase from the previous quarter, including $137 million linked to the oilpatch.

Impaired loans to the oilpatch soared to $183 million in the third quarter -- almost four times the $46 million recorded in the previous quarter.

RBC is the second bank to report an increase in impaired loans in the May to July quarter. On Tuesday, the Bank of Montreal (TSX:BMO) reported the oil and gas sector's impaired loans grew $80 million from the previous quarter to $106 million.

Analysts say impaired loans to the oilpatch are manageable for Canada's biggest lenders. The real trouble could come if consumer loans, such as residential mortgages, begin to suffer due to a rise in unemployment -- an impact that would take some time to materialize.

Mark Hughes, RBC's chief risk officer, said the bank's consumer loan book isn't showing any signs of stress.

Edward Jones analyst Jim Shanahan said it takes longer for consumer loans to be impacted because companies tend to trim other expenses before they cut payroll.

"They don't want to lay people off and then realize that the weakness that they're observing in their business is just temporary," Shanahan said.

Once mass layoffs do occur, it will take several months before households begin defaulting on their mortgage payments, Shanahan said.

Although RBC's results met analyst expectations, the stock took a hit Wednesday. RBC shares were trading at $71.03 Wednesday afternoon -- a decrease of $1.33, or nearly two per cent from the previous day's close.

Barclays analyst John Aiken says RBC's domestic retail banking and international banking businesses posted solid results.

However, earnings results from other segments -- which are expected to fuel growth in the quarters ahead, as consumer borrowing slows -- moderated, therefore "souring" the outlook on the stock relative to its peers, Aiken said in a note to clients.

RBC Capital Markets had $545 million of net income, down 15 per cent or $96 million from last year's record high.