Merck, Twitter earnings eyed on Wall Street

Wall Street looked set for a lower open on Monday, as traders focused on big third-quarter earnings from Merck, T-Mobile US and Twitter.

Six Dow-listed companies will report this week before the markets open on Monday. A raft of 143 S&P 500 companies will post numbers during the week.

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Merck's quarterly earnings beat analysts' expectations. Earnings fell to 90 cents per share from 92 cents in the year-earlier period. Revenue slipped to $10.56 billion from $11.03 billion a year ago.

Analysts had expected the firm to post earnings of 88 cents a share on revenue of $10.67 billion.

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The market mood is expected to be cautious ahead of a two-day Federal Reserve meeting beginning on Tuesday. Speculation is high as to whether the central bank will announce an end to its bond-buying program and hint as to the timing of a hike to record-low interest rates.

"We expect a $15 billion taper to end quantitative easing, and little change in rhetoric," said economists at Mizuho Bank in a report.

Economic data due on Monday include pending home sales data for September.