JPMorgan Chase’s strong second-quarter performance surprised investors, but it’s no time to celebrate.

As the first big Wall Street bank to report financial results, JPMorgan posted near record profit of $5.43 billion, or $1.27 a share. Even more surprising, revenue rose 7 percent, thanks to growth in investment banking.

While CEO Jamie Dimon proved once again that his bank is better equipped than most to handle adversity, the firm is facing continued threats to its bottom line, in particular mounting mortgage-related losses.

The bank’s mortgage-related costs alone are expected to be between $4 billion to $6 billion. That includes costs for fixing the foreclosure fiasco and a potential multi-billion dollar mortgage settlement with federal regulators and 50 state attorneys general.

“There have been so many flaws in mortgages that it’s been an unmitigated disaster,” Dimon said during a conference to discuss results.

Some analysts estimate that JPMorgan may have a war chest of as much as $8 billion set aside for paying government fines and settling a stream of mortgage-related litigation.

” [Dimon] may be the most aggressive in taking reserves against mortgage losses,” said Paul Miller, a bank analyst at FBR Capital Markets.

The looming payouts are a stark reminder of the host of issues confronting the bank, ranging from declining trading revenues and weak loan growth to Europe’s debt woes and a raft of new regulations.

Indeed, JPMorgan is expecting to take a $1 billion annual revenue hit from new rules limiting the fees it can charge retailers for debit-card transactions. Sources said that the firm expects to “mitigate” those losses by eliminating free checking.

“We’re not going to do anything that’s not consumer- friendly,” Dimon stressed during the conference call.

The firm also has about $15 billion in exposure to troubled euro zone nations Spain and Italy, which are struggling under mountains of debt.

Still, investors cheered the fact that the bank rang up more profits than many were expecting and was able to cut its reserves for bad loans. The bank took down $1 billion in reserves in its credit-card division.

The results boosted hopes for the rest of the banking sector. Shares of JPMorgan rose as much as 4 percent before closing at $40.35, up 1.84 percent. mark.decambre@ypost.com