DUBAI, Oct 25 (Reuters) - Saudi Telecom Co (STC) has hired banks to arrange a potential initial sale of shares in its products and services development arm, Solutions by STC, three sources familiar with the matter told Reuters. STC, Saudi Arabia’s largest telecoms operator, has appointed HSBC, Morgan Stanley and the investment banking arm of Saudi lender National Commercial Bank to advise on the sale, said the sources, who declined to be identified as the matter is not public.