OVERSEAS <OSG> SEES OPEC QUOTAS KEY TO RATES Overseas Shipholding Group Inc president Morton Hyman said if oil production by OPEC rises during the second half of 1987, freight rates for tankers should rise accordingly. Hyman, delivering a speech at the annual shareholders meeting, said international tanker markets were generally weak throughout the first quarter, but since the end of March OPEC oil production has picked up. The result has been a modest improvement in tanker rates. Overseas said 73 pct of its fleet handles liquid cargo. He said tanker requirements decreased in September 1986 as OPEC production quotas dropped and levels of oil stocks rose. For the first quarter 1987, the company reported net income of 10.3 mln dlrs, or 40 cts per share, compared to 9.3 mln dlrs, or 36 cts per share, for the comparable quarter a year ago. The company reported net income for 1986 of 37.3 mln dlrs, or 1.45 dlrs per share. "The improvement in the company's 1986 results, after four years of declining earnings, reflects a sharp, albeit temporary, rise in freight rates in the international tanker markets last summer," Hyman said. He said the Alaskan oil trade continues to be the principal source of employment for its U.S. flag tanker fleet, which represents approximately 15 pct of the company's tonnage. Overseas owns and operates 67 vessels.