Updated from 11:11 a.m. EDTShares of most major oil companies moved lower Tuesday morning in concert with crude oil's price drop. Sunoco ( SUN), after being up as much as 88 cents in the session, finished down 8 cents to $28.19. JPMorgan upgraded the refiner from neutral to overweight Tuesday morning. Light, sweet crude oil futures for May delivery settled lower by $1.90 to $49.15 a barrel on the New York Mercantile Exchange. The Amex Oil Index was down 2.5%, or 22.56 to 868.19. Shares of Royal Dutch Shell ( RDS.B) were off 3.9%, to $42.94. ConocoPhillips ( COP) shares were down 3.6% to $39.69. Chevron ( CVX) was lower by 2.1% to $68.40. BP ( BP) shares were down 2.6% to $39.64. Exxon Mobil ( XOM) was lower by 1.9% to $68.71.