BENGALURU, Jan 12 Reuters Indian shares fell for the third session in a row on Thursday, with investors on edge ahead of earnings from IT companies after TCS39;s warning earlier this week and key domestic and U.S. inflation data for cues on the likely path for rate hikes.

The Nifty 50 index closed 0.21 lower at 17,858.20, while the SP BSE Sensex declined 0.25 to 59,958.03. Both indexes opened higher before reversing course, as they have in each of the previous two sessions.

India39;s retail inflation in December likely held steady from November, a report due at 530 p.m. IST is expected to show. Still, the central bank head has pledged to continue fighting inflation despite the worst being behind us.

While the expectations suggest a cooling off in inflation, a lot depends on the commentary on the data as well as the components of price changes, said Narendra Solanki, head of fundamental research for investment services at Anand Rathi Shares and Stock Brokers.

Nine of the 13 major sectoral indexes declined, led by the oil gas index39;s 1.02 drop. Oil prices rose 3 overnight, which hurts top importers such as India.

The volatility will remain ahead of key IT earnings, Solanki said.

Infosys Ltd and HCL Technologies Ltd closed 0.64 and 1.60 higher ahead of their quarterly reports due after the bell. IT stocks overall were up 0.43.

Investors are wary since top IT company Tata Consultancy Services missed profit estimates earlier this week and flagged challenges about…