Sony Corp on Monday unveiled a new high-end Xperia handset featuring an aluminium frame and a 5.2-inch screen, showing it is still in the smartphone race even as it scales down its struggling mobile operations. The launch of the new flagship model comes amid a painful restructuring at the Japanese consumer electronics giant which has thrown the future of its smartphone division into doubt. But as the company focuses on cutting costs rather than growing its mobile market, the division still needs investment in new products and marketing to maintain Sony’s brand and hold off a more rapid deterioration. The Xperia Z4 would be available in Japan around the middle of the year, though it did not provide a launch date, details on carrier partners or price. The handset would be available in four colours and was slightly thinner than the previous Z3.