Mumbai, Apr 12 (PTI): A build-up in tension linked to geo-political developments gave markets the blues today as the Sensex lost 145 points at 29,643 while domestic investors sat tight ahead of the corporate earnings season.

Industrial output data for February and retail inflation for March, slated for release after the market hours, heightened the sense of uncertainty.

After starting higher, the 30-share Sensex slipped into negative territory before settling down 144.87 points, or 0.49 per cent at 29,643.48.

The gauge had bounced 213 points in the previous session.

The 50-issue NSE Nifty ended 33.55 points, or 0.36 per cent, lower at 9,203.45 after cracking below 9,200.

Sentiment soured over rising military heat in the Middle East and Korean peninsula following last week's US strike against Syria and sabre-rattling by the US and North Korea.

Besides, the rupee falling by 23 paise to 64.73 against the US dollar (intra-day) added to negativity.

Caution prevailed ahead of the fourth quarterly earnings season with Infosys unveiling its numbers tomorrow.