* Intel and other chipmakers decline on China tariff
* Chevron, Exxon Mobil rise on higher oil prices
* Indexes down: Dow 0.65 pct, S&P 0.41 pct, Nasdaq 0.2 pct (Updates to early afternoon)
By Aparajita Saxena
June 18 (Reuters) - The three major U.S. stock indexes were trading lower on Monday, but came off session lows, as gains in energy shares eased fresh concerns over a possible trade war following China's retaliation against U.S. tariffs.
U.S. President Donald Trump said last week he was pushing ahead with hefty tariffs on $50 billion of Chinese imports, prompting a swift response from Beijing, which said it would slap duties on several American commodities.
Boeing, the single largest U.S. exporter to China, fell nearly 1 percent, while construction equipment maker Caterpillar declined 1.4 percent.
Intel was the biggest drag on the S&P 500 and the Nasdaq on China tariff concerns and a downgrade by Northland Securities. A host of other chipmakers, which depend on China for a larger part of their revenues, also slipped.
"Right now, trade developments are moving in a 'two-steps-forward-one-step-back' type of pattern," said Meghan Shue, a senior investment strategist at Wilmington Trust in Delaware.
"Friday was a step back, but we continue to believe this is part of the administration's negotiation strategy to secure better trade terms," she said.
Oil prices rose in volatile trade on Monday ahead of this week's OPEC meeting, where top producers are widely expected to push for higher output. Despite this anticipated increase, Goldman Sachs maintained its bullish outlook on the oil market.
Chevron Corp rose nearly 2 percent and was the top gainer on the Dow Jones, while Exxon Mobil gained 0.6 percent.
The energy index rose 1.5 percent, with 30 of its 31 constituents posting gains.
At 12:23 p.m. ET, the Dow Jones Industrial Average was down 162.83 points, or 0.65 percent, at 24,927.65, on track for a fourth straight session of losses. The S&P 500 was down 11.39 points, or 0.41 percent, at 2,768.27 and the Nasdaq Composite was down 18.20 points, or 0.23 percent, at 7,728.18.
The consumer staples index fell 1.7 percent, with tobacco giant Philip Morris down 3.2 percent. Tobacco is among the 545 U.S. goods that China will impose tariffs on from July 6.
The S&P financial index was down 0.3 percent after yield on the U.S. 10-year note slipped.
Among other stocks, Valeant Pharmaceuticals' U.S.-listed shares fell nearly 8 percent after the U.S. health regulator declined to approval the company's plaque psoriasis treatment lotion.
Biotechnology firm China Biologic gained 21 percent after Chinese investment giant CITIC Capital Holdings offered to buy it in a deal valuing the company at $3.65 billion.
Declining issues outnumbered advancers on the NYSE for a 1.23-to-1 ratio on the downside, and for a 1.42-to-1 ratio on the Nasdaq.
The S&P 500 index showed 16 new 52-week highs and 4 new lows, while the Nasdaq recorded 131 new highs and 35 new lows.
Reporting by Aparajita Saxena and Ankur Banerjee in Bengaluru; Editing by Sriraj Kalluvila