Apple stock hit its highest levels in four years yesterday, closing at $50.30.

The action continued in after hours trading, where the company gained another US cent. The company saw stocks climb $2.33 during the day, a 4.86 per cent increase. The move follows Apple's best financial quarter for four years, and good reception for its new iPod Photo, U2 iPod and iTunes Europe (and Canada) plans.

Positive uplift also comes from Apple's introduction last week of iBooks, a low-end Power Mac G5, and recent news that IBM will raise its G5 manufacturing by 40 per cent.

Merrill Lynch raised its estimates once again for Apple, repeating its observation of success in iPod sales driving Mac sales.

The analyst now anticipates first quarter 2005 earnings of 42 cents per share on revenue of $2.95 billion, up from previous targets. It rates Apple a 'buy' with a price target of $49. "Apple's growth and margins now are more in line with Dell's", the company said.

The news also reflects Apple CEO Steve Jobs' recent assertion that iPod presently commands 92 per cent of the world trade in hard-drive based music players, and that Apple has seen 64 per cent increase in song sales through its global iTunes Music Store service since May.

Apple has sold 17.72 million songs so far this month, he said.