Stocks fell on Monday as energy stocks retreated on falling oil prices and Boeing Co slid after it issued a profit warning, giving investors jitters ahead of key earnings reports this week.

Exxon Mobil fell 1.9 percent to $68.55, while Chevron Corp lost 3.4 percent to $66.90. U.S. front month crude fell 6 percent to $49.14 per barrel after the International Energy Agency lowered its demand forecast.

Adding to concern over earnings season Boeing Co said after the bell on Thursday first-quarter profit would be slashed by lower-than-expected airplane prices and production cuts on its lucrative widebody planes, sending the stock down 6 percent.

Shares of General Motors were another casualty of the session's pullback, falling more than 16 percent after a newspaper report the U.S. Treasury Department is directing the troubled automaker to prepare for a bankruptcy filing by June 1 despite the company's contention that it could reorganize outside the court. GM's stock fell more than 15 percent to $1.71.

Goldman Sachs , JPMorgan , Citigroup and General Electric are all set to report their latest quarterly results this week.

A lot of what happens this week will depend on the earnings of those financial companies, said Hugh Johnson, chief investment officer of Johnson Illington Advisors in Albany, New York

Every professional investor knows you cannot sustain the kind of moves we've had in the last five weeks, so having corrections in the early stages is more than predictable.

The Dow Jones industrial average <.DJI> dropped 113.90 points, or 1.41 percent, to 7,969.48. The Standard & Poor's 500 Index <.SPX> fell 9.02 points, or 1.05 percent, to 847.54. The Nasdaq Composite Index <.IXIC> lost 21.45 points, or 1.30 percent, to 1,631.09.

The S&P 500 closed out a five-week rally on Friday which boosted the broad-based stocks gauge 25.7 percent from closing lows on March 9. However, the index is still down 5.9 percent on the year.

Boeing, the chief drag on the Dow, fell 6.3 percent to $36.68. Barclays cut its price target on the stock to $50 from $66 on Monday morning.

Bank stocks added to gains seen on Thursday, following upbeat preliminary results from Wells Fargo & Co. The KBW Bank index <.BKX> up 3.5 percent. Citigroup rose 13.6 percent to $3.45.

On Nasdaq, Qualcomm fell 2 percent to $40.8 as shares of semiconductor companies gave up some of their gains from the recent advance. The semiconductor index <.SOXX> fell 3 percent.

Yahoo Inc bucked the trend, rising 7.2 percent to $14.44 after a report that company executives met with Microsoft to discuss potential partnerships between the companies' Internet search and advertising operations.

In merger news Express Scripts Inc has agreed to buy WellPoint Inc's NextRx subsidiaries for $4.68 billion, the companies said in a statement. Express Scripts fell rose 8.5 percent to $53.36, while WellPoint rose 4.64 percent to $42.26.

(Additional reporting by Leah Schnurr)

(Editing by Theodore d'Afflisio)