Investors will be looking to see whether the continued flow of first-quarter earnings this week will be able to help the market extend recent gains. Public Power Corporation, Greece’s biggest electricity producer, is scheduled to release first-quarter figures tomorrow. Analysts expect PPC to report a net income of 190 million euros versus 30 million euros in the same period a year earlier. Refinery Hellenic Petroleum is expected to report first-quarter figures on Wednesday when Frigoglass, the world’s largest maker of drinks refrigeration equipment, is scheduled to announce earnings figures. On Friday, the Athens bourse’s benchmark general index added 1.04 percent to 2,146.15 points, bringing gains in the last month to 11.30 percent. Wall Street stocks churned lower Friday amid lackluster economic data and news that General Motors planned a major cut in the number of its dealers, which could add to the labor market’s woes.