(Corrects to Wednesday in first paragraph)
* IBM drag on tech sector as profit margin misses estimates
* Morgan Stanley profit shines on trading boost
* Oil jumps, energy stocks lead gains on S&P
* CSX, United Airlines boost Dow Transports after strong results Indexes: Dow off 0.14 pct, S&P up 0.02 pct, Nasdaq off 0.12 pct
By Sruthi Shankar
April 18 (Reuters) - The benchmark S&P 500 index posted slight gains on Wednesday, helped by gains from industrial and energy stocks, but IBM's disappointing results and a sell-off in semiconductor stocks weighed on the Nasdaq and the Dow.
IBM fell 6.2 percent after the company reported quarterly profit margins that fell short of Wall Street expectations.
Semiconductor stocks also took a hit, led by Lam Research's 5 percent drop after what analysts called a disappointing shipment forecast. The S&P technology index fell about 0.5 percent.
Not all results were disappointing. Morgan Stanley rose 3 percent after it reported a 40 percent jump in quarterly profit, driven by its trading business.
United Airlines rose 1.6 percent after reporting a rise in profit and CSX Corp jumped 7 percent after the railroad operator topped profit estimates. That helped lift the Dow Jones Transport index by 1.2 percent.
Oil prices jumped about 2 percent, lifted by a reported decline in U.S. crude inventories and the risk of supply disruptions. Exxon and Chevron were up about 1.3 percent.
S&P 500 companies are expected to post an 18.6 percent rise in profits in the first quarter, the biggest increase in seven years, according to Thomson Reuters data.
Stocks have gained solidly in the past two days after strong results from industry bellwethers as well as positive economic data helped investors turn attention away from geopolitical and trade tensions.
At 10:08 a.m. ET, the Dow Jones Industrial Average was down 0.14 percent at 24,751.47. The S&P 500 was up 0.02 percent at 2,707.05 and the Nasdaq Composite was down 0.12 percent at 7,272.62.
Advancing issues outnumbered decliners on the NYSE for a 1.84-to-1 ratio, and on the Nasdaq, for a 1.27-to-1 ratio. (Reporting by Sruthi Shankar in Bengaluru; Editing by Shounak Dasgupta)