Shares of major integrated oil companies were moving lower Tuesday as four giants were downgraded by Oppenheimer Tuesday morning.

Chevron ( CVX), BP ( BP), Exxon Mobil ( XOM) and ConocoPhillips ( COP) were lowered from outperform to perform.

Chevron, which warned on its first-quarter results late Thursday, was recently trading down 2% to $66.62.

BP was lower by 1.7% to $39.25.

Exxon Mobil was off 1.6% to $66.93.

ConocoPhillips was down 0.3% to $39.94.

The Amex Oil Index was lower by 0.6%, to 880.82.Light, sweet crude oil futures for May delivery were recently hovering around $50 a barrel, down 23 cents to $49.82.

Sunoco ( SUN) was trading at $28.07, down 1.4%.

Royal Dutch Shell ( RDS-B) was down 1.7% to $41.67.

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