Indian stock markets remained positive for the fourth straight week ended September 24, as the 30-share index Sensex increased by 450.43 points (2.30%) to 20,045.18 and the broad-based Nifty surged 133.35 points to close the week at 6,018.30.

It was for the initial time after January 17, 2008 that the BSE Sensex hit the 20000 mark on the back of hefty buying activity by FIIs.

The Sensex surged 2047 points in a period of four weeks.

The BSE Midcap index gained 10.88 points to 8,115.16 and the BSE Small-Cap index went up by 28.42 points to 10,267.33.

On Thursday, the country's administration increased the limits of foreign investment by two fold in administrative securities to $10 billion as against $5 billion.

Moreover, the administration raised the limit for corporate bonds to $20 billion as against $15 billion. The governmental move would assist to lift up investment in bonds, infra and strengthen bond markets in the country.

During the initial two trading sessions, the Sensex gained 406.80 points on account of speculative demand from local operators together with sturdy worldwide signals.

On Tuesday, the Sensex hit 20K mark to end the day at 20,001.55 and Nifty also gained 28.60 points to mark its closure at 6,009.05.

On the next two days, the Sensex remained silent as it lost 140 points and Nifty diminished 49.50 on account of profit booking.

On Friday, the Sensex regained its 20K mark, as foreign funds continued to pump capital into Indian bourses, strengthened by the administration's shift to calm down certain foreign investment limits.

At the week's last day, the Sensex gained 184.17 points, while the Nifty soared 58.75 points to 6018.30.

The gainers' list comprised Hindustan Unilever Ltd, Housing Development Finance Corporation (HDFC), Maruti Suzuki India, Hero Honda Motors, ITC, Wipro, Tata Power Company and Tata Steel.

The losers' list comprised Reliance Industries Ltd, Jindal Steel & Power and Jaiprakash Associates.