The S&P BSE Sensex extended losses for the third straight session on Wednesday, falling by 213 points, mainly led a weakness in global markets as investors remained cautious amid the ongoing two-day meeting of the US central bank.

The Sensex closed at 27,039 points, down 0.78%, while the 50-share Nifty fell by 61 points, or 0.33%, to end at 8,171.

Sentiment remained weak ahead of policy statement release by the US Federal Reserve, even though the markets widely expect it to keep rates unchanged.

"Given the souring tone of recent US economic data and mixed signals from Fed officials, the central bank is very likely to keep rates unchanged yet again. However, we expect the FOMC statement to leave the door open for a rate hike in December if the US economy performs in line with the bank's forecast of continued moderate growth and higher inflation," said Nordea Markets in a note.

Investors also stayed cautious ahead the Futures & Options (F&O) expiry of October series on Thursday.

Among the BSE sectoral indices, Bankex, Power and Realty were the top losers, while Consumer durables index was the top gainer.

Axis Bank shares plunged over 7%, as concerns rose over its asset quality after the bank sold loans worth Rs.1,850 crore to asset reconstruction companies (ARCs), Business Standard reported.

"While growth and margin performance was strong, the key disappointment in Axis Bank's Q2 FY16 result was significant accretion to impaired assets. Though near-term asset quality outlook is uncertain, the bank is estimated to accelerate earnings growth in coming years on the back of further pick-up in loan growth and an efficiently managed cost metric," said Amar Ambani, Head of Research, IIFL.

Lupin shares continued posting losses for the second consecutive session and were down 1.8%. The pharma company reported 35% drop in its net profit for the second quarter in the current fiscal year.

Tata Motors shares ended 0.7% higher after the company reported 21% increase in its global sales to 97,102 units in September.

On the commodities front, gold prices rose sharply by Rs 155 to Rs 27,265 per 10 grams as the US dollar remained weak ahead of the Fed statement. Silver prices also closed higher at Rs 37,350 per kg, up Rs 225.