Apple shares climbed slightly on heavy trading yesterday after analysts at American Technology Research and Piper Jaffray offered optimistic advice to clients.

The company's shares closed at $52.37 last night, up 3.4 per cent on the day's trading.

Recently, analysts have been warning that iPod sales may impact on company performance in Apple's current quarter. Its shares have lost value as investors mull over the speculation, but the company will reveal the facts about its business operations tomorrow (July 19).

Analyst Shaw Wu of American Technology Research told clients: "We anticipate Apple to report results at the upper end, if not in excess, of its guidance of $4.2-4.4 billion in revenue." He recommends his clients buy Apple stock.

Wu expects Apple to reveal it has sold 8.3 million iPods and 1.2 million Macs in its third quarter of 2006 financial year. He anticipates the company will reach $5 billion in revenue for its upcoming fourth quarter, but that Apple will target a guide figure of a more conservative $4.6 billion.

Piper Jaffray analyst Gene Munster was more optimistic. He upgraded his assessment of Apple's performance to tell clients that he expects the company to deliver results "at the high end" of its targets.

Munster cites checks with Apple resellers, and anticipates strong MacBook sales coupled with slightly softer iPod sales.