Aug 19 Reuters Australian corporate earnings have been a positive surprise amid investor euphoria over estimatebeating margins, but historical trends suggest results could take a turn as the earnings season approaches its end, Macquarie analysts said.

Companies have posted betterthanexpected margins, often supported by lower tax and interest costs, with most of them outperforming market view so far this season than in February, Macquarie said in a note.

The upbeat earnings have prompted investors to add back to their portfolio, especially after reducing their equity exposure in the recent correction at the start of the month, the analysts noted.

Cyclical retailers were the standouts last week. Shares of JB HiFi posted their best weekly gain in more than four years after the consumer electronics retailer announced a special dividend last week and an estimatebeating annual results.

Top telco Telstra also came as a positive surprise after it raised its earnings forecast.

Investors appeared to shrug off the drop in profit from leading Australian banks, and instead focused on the positives such as Commonwealth Bank of Australia39;s lower provision for bad loans and National Australia Bank39;s steady margin.

Still, the biggest disappointment came from Origin Energy, whose shares crashed on a warning that profit in its electricity generation business is likely to drop.

The cycle is slowing and the key uncertainty is how much it improves in reaction to rate cuts by the…