DOW JONES NEWSWIRES Occidental Petroleum Corp.'s (OXY) first-quarter earnings edged up 0.7% as the exploration and production company benefited from higher production and strong oil prices. Occidental's heavy investment in the U.S.--in California, Texas and the interior of the country--has boosted production recently. Last week, Moody's Investors Service raised Occidental's rating a notch, partly due to the company's significant cash reserves. Average daily oil and natural-gas production grew 3.4% from a year earlier to 755,000 barrels of oil equivalent per day. Average prices increased 17% for oil, while natural-gas liquids prices edged down 0.3% worldwide. Natural-gas prices dropped by nearly a third. Occidental reported a profit of $1.6 billion, or 1.92 a share, up from $1.55 billion, or $1.90 a share, a year earlier. Excluding prior-year write-downs, year-earlier earnings from continuing operations were $1.96. Revenue grew 9.4% to $6.27 billion. Analysts polled by Thomson Reuters were expecting earnings of $1.92 a share on revenue of $6.13 billion. Revenue in the company's main oil and gas segment rose 12% as profit increased 1.4%. Chemical sales fell 1.4% while profit was down 16%. Shares closed at $90.11 Wednesday and were inactive in recent premarket trading. The stock has fallen 3.8% this year, trailing the broader market. --By Anne Pallivathuckal and Tess Stynes, Dow Jones Newswires; 212-416-2481; Tess.Stynes@dowjones.com