U.S. stock index futures fell on Thursday as downbeat earnings from Cisco and Credit Suisse weighed ahead of data on the struggling jobs market.

* Cisco Systems Inc shares tumbled 8.5 percent to $20.16 in premarket trading a day after the network equipment maker warned about dwindling public spending and reported weaker quarterly margins.

* Overseas, earnings also hurt overall sentiment toward equities, with European shares off nearly 1 percent after major European bank Credit Suisse missed profit expectations because of debt charges. Its U.S.-traded shares dropped 5 percent to $44.30.

* S&P 500 futures fell 7.7 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures tumbled 54 points, and Nasdaq 100 futures were off 20.25 points.

* PepsiCo Inc
and Sprint Nextel Corp reported quarterly results early Thursday.

* Expedia Inc , Kraft Foods Inc and Goodyear Tire and Rubber Co are also due to report earnings.

* Debt yields rose in peripheral European counties on concerns over a lack of a concrete policy to tackle the euro zone debt crisis, further hurting risky assets. The U.S. dollar rose versus the euro and pulled commodity prices lower.

* Weekly jobless data, closely followed to track the recovery of the labor market, is due at 8:30 a.m. EST. Economists in a Reuters survey forecast a total of 410,000 new filings for unemployment benefits, compared with 415,000 in the prior week.

* At 10 a.m. EST, the Commerce Department releases wholesale inventories for December. Economists forecast a 0.7 percent rise versus a November decrease of 0.2 percent.

* Google Inc and Facebook Inc among other companies have held low-level takeover talks with Twitter that would give the micro-blogging site a value as high as $10 billion, the Wall Street Journal reported.

* Computer security firm McAfee Inc said hackers working in China broke into computer systems of five multinational oil and gas companies to steal bidding plans and other critical proprietary information.

* On Wednesday, investors took profits after a recent rise in U.S. stocks, but a late push helped the Dow squeeze out its eighth straight day of gains.

(Reporting by Rodrigo Campos; editing by Jeffrey Benkoe)