San Francisco - Apple unveiled new Macs ahead of the holiday shopping season and said its latest computer operating system, Mavericks, is available free of charge.The Cupertino, California-based company made the announcement on Tuesday at an event in San Francisco. A new, 33cm MacBook Pro with Retina display is thinner and lighter, said Apple marketing chief Phil Schiller, adding that the laptop has up to 9 hours of battery life, enough to "watch the entire trilogy of The Black Knight on one charge". The notebook's new price is lower: $1 299, compared with $1 499 for the previous version.A larger MacBook Pro, with a 38cm monitor and 256GB of storage starts at $1 999, compared with $2 199 for the previous version.The Mac Pro, a high-end desktop computer aimed at what Apple calls "power users", will be available in December for $2 999.Apple also says nearly two-thirds of its mobile devices are running iOS7, the revised operating system it released in September. Twenty million people have listened to iTunes Radio about a month after its release.Apple is expected to revive its tablet line with new iPads. The company sold 14.6 million iPads in the June quarter, down 14% from the same time last year.