* Google, IBM shares fall a day after posting earnings
* Morgan Stanley shares rally after results
* Futures: Dow off 10 pts, S&P flat, Nasdaq up 3 pts
NEW YORK, April 17 (Reuters) - U.S. stock index futures were flat and pointed to a lower open on Thursday after three days of gains on Wall Street, weighed by results including those from Google and IBM and ahead of employment and regional business growth data.
* Data on weekly applications for unemployment insurance and the Philadelphia Fed's business index is due at 8:30 a.m. EDT (1230 GMT) and 10:00 a.m. (1400 GMT) respectively.
* Google shares fell 2.5 percent in premarket trading and IBM lost 4 percent after both reported underwhelming earnings results late Wednesday. Their results raised questions about those of other tech-sector companies.
* Shares of Morgan Stanley, however, rose after it reported a 49 percent rise in first-quarter earnings before the open on Thursday. General Electric posted a 12 percent rise in overall industrial profits and its shares gained 1 percent in premarket trading.
* S&P 500 e-mini futures were little changed and fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract, pointed to a lower open. Dow Jones industrial average futures fell 10 points and Nasdaq 100 futures added 3 points.
* Wall Street rallied 1 percent on Wednesday after Federal Reserve Chair Janet Yellen said persistently low inflation poses a more immediate threat to the U.S. economy than rising prices, stressing that the U.S. central bank would be delivering policy stimulus for some time to come.
* China's Weibo Corp will be valued at $3.46 billion when it goes public on the Nasdaq on Thursday, as it priced at the lower end of expectations on concerns about the microblogging service's slowing user growth and the country's highly censored media environment. (Reporting by Rodrigo Campos; Editing by Bernadette Baum)