US stocks extend gains in early trade on Tuesday after a report showed that manufacturing activity rose at a faster pace than expected in January.

The S&P 500 Index advanced 15.60 points, or 1.21 percent, to trade at 1,301.76 at 11:00 a.m. EDT. The Dow Jones Industrial Average advanced 96.61 points, or 0.81 percent, to trade at 11,988.54. The Nasdaq Composite Index advanced 1.42 percent.

The Institute of Supply Management (ISM) Manufacturing Index, which measures the amount of manufacturing activity that occurred in the previous month, rose better than estimated to 60.80 in January from 58.50 in December, while analysts expected a reading of 58.20. The key employment index advanced to 67.8 in January compared to 61.7 in the previous month.

Earlier stocks started off February with gains, after Dow recorded its biggest January rally since 1997 in the previous month. String of upbeat corporate earnings also boosted investor sentiment.

Pfizer Inc. (NYSE:PFE) shares gained 4.17 percent after the company said its fourth-quarter profit rose to $2.89 billion or $0.36 per share from $767 million or $0.10 per share in the same quarter last year.

Archer Daniels Midland Co. (NYSE:ADM) shares surged 6.70 percent to $34.87 as its second quarter earnings rose to $732 million or $1.14 per share, up from $567 million or $0.88 per share in the same quarter last year.

Shares of Baidu, Inc. (BIDU) climbed 7.53 percent following its better-than-expected fourth quarter earnings. Adjusted profit was 1.19 billion Chinese yuan, up from 0.45 billion Chinese yuan last year. Adjusted earnings per share was 3.40 Chinese yuan or $0.52.

The euro gained 0.60 percent to 1.3775 against the dollar and the yen gained 0.45 percent against the greenback.

Crude oil futures declined 0.59 percent to $91.65/barrel and gold futures declined 0.31 percent.