The city was effectively closed after a leader from the Muttahida Quami Movement, the dominant party in Pakistan's key financial city, was shot dead.

‘Owing to law and order concerns, the Karachi Stock Exchange witnessed a dull session,’ said Samar Iqbal, a dealer at Topline Securities Ltd.

KSE 100 index ended 0.75 percent, or 90.53 points, lower at 11,945.36.

Volume fell to 50.67 million shares from 76.1 million shares traded on Monday.

Dealers said the market's response to the assassination of al Qaeda leader Osama bin Laden in Pakistan was largely muted.

In the currency market, the rupee gained versus the dollar to end at 85.28/35, compared with Monday's close of 84.54/64 amid a lack of import payments.

The rupee has performed strongly in recent months, hitting an 11-month high last month, thanks largely to a record inflow of remittances, strong foreign exchange reserves, healthy exports and a current account surplus, according to analysts and officials.

Remittances increased by 22.37 percent to more than $8 billion in the first nine months of the 2010/11 fiscal year, and in March a record $1.05 billion was received, according to data from the State Bank of Pakistan.

In the money market, overnight rates were flat at 11.10 percent, unchanged from Monday's close and dealers said rates are likely to stay on the lower side amid increased liquidity in the interbank market.