Updated from 12:41 p.m. EDT Shares of most major integrated oil companies finished lower Monday as crude oil prices dropped. Light, sweet crude oil futures for May delivery settled down $1.46, or 2.8%, to $51.05 a barrel on the New York Mercantile Exchange. The Amex Oil Index was down 2.3%, or 20.6 points to 890.61. Royal Dutch Shell ( RDS.B) shares closed down 3.4%, or $1.55 to $44.68. Shares of BP ( BP) were lower by 1.5%, or 62 cents to to $40.71. ConocoPhillips ( COP) shares were down 2.8%, or $1.20 to $41.16. Chevron ( CVX) shares were down 0.8%, or 59 cents to $69.89. Shares of Exxon Mobil ( XOM) were down 0.4%, or 39 cents to $70.05. Despite the global economic downturn, Exxon Chairman and CEO Rex Tillerson said the world's largest publicly traded oil company expects to spend $129 billion on new projects over the next five years. That figure "spans across the entire scope" of the Irving, Texas-based company's business, including oil and gas exploration as well as refining, he said. "Our business plans are developed with a very long view in mind," Tillerson said after the inauguration of a liquefied natural gas plant in the Persian Gulf state of Qatar. "So the fact that we're in a temporary economic downturn -- and it will be temporary; it will turn -- really does not affect our business plans at all." Exxon has benefited from years of high oil prices and hoarding cash, putting it in better position to weather the recession than many U.S. companies and some industry peers. Exxon posted a record profit last year of $45.2 billion and had $31 billion in cash at the end of 2008.