Hong Kong insurance companies are developing more online sales channels and introducing more medical and retirement products to boost sales as the sector is poised for its worst slump on record, according to industry players.Mainland Chinese, until now huge spenders on Hong Kong insurance policies, spent only HK$839 million (US$108 million) on them in the second quarter, down 85 per cent from the first three months. In the first half, their spending dropped 76 per cent year on year, according…