Sea Ltd.’s e-commerce arm turned its first quarterly profit on an adjusted basis, a sign it’s holding its own against bigger Chinese rivals in Southeast Asian markets like Indonesia.Shares of Sea rose about 7% in pre-market US trading after net income for the company as a whole topped estimates at $153.3 million. Analysts expected $128.6 million on average. Sales rose 31% to $4.3 billion in the three months through September, exceeding the average estimate of $4.1 billion....