WARM weather on top of healthy property gains helped Hongkong Electric Holdings post a 33 per cent rise in profit attributable to shareholders to $1.73 billion for the first six months. Turnover jumped 17 per cent to $3.04 billion, with earnings per share of 86 cents. An interim dividend of 37 cents will be paid. Chairman George Magnus said unit sales of electricity rose 10.1 per cent during the period under review, as a result of the warm weather in April and May. The sales growth was better than expected, compared with last year's sales rise of 7.4 per cent and Hongkong Electric's long-term forecast growth of between five and seven per cent per annum. For the first six months, sales to commercial customers, accounting for 70 per cent of Hongkong Electric's total unit sales, increased 10.5 per cent. Sales to domestic customers rose 12.4 per cent, with the sector making up 23.2 per cent of the company's total unit sales. But sales to industrial customers, which accounted for 6.8 per cent of electricity sales, dropped 1.1 per cent. Mr Magnus said electricity sales to commercial and domestic customers would continue to see ''good growth'', while the decline in sales to industrial customers would have less impact as the sector was becoming less important to the company. During the period under review, Hongkong Electric saw a significant improvement in operating profit, which jumped 33 per cent to $1.76 billion. Associated property company Secan contributed pre-tax profit of $415 million, compared with $112 million a year ago. Secan, a joint venture with Cheung Kong (Holdings) - its ultimate holding company - received occupation permits in the first half for its Eastern Commercial complex and for the final five towers of phase three at the South Horizons development. Steady progress was also made for the fourth phase of South Horizons. Hongkong Electric gave no explanation for the faster growth of operating margin. Sun Hung Kai Research analyst Anna Tong suspected the rise was due to effective cost control and the contribution from its engineering consultancy subsidiary, Associated Technical Services. Mr Magnus said the subsidiary ''achieved steady progress on its various projects in the Middle East, Southeast Asia and China''. But Ms Tong expected Hongkong Electric to report a slower rise in full-year earnings, of 9.3 per cent to $3.69 billion, compared with the previous year's 10.8 per cent rise. She said the slower growth was a result of lower full-year profit contribution from the property operation. She estimated an after-tax property profit of $547 million for the current year, compared with $590 million last year.