RIYADH, 23 October — The Saudi Arabian Monetary Agency cancelled 58 stock market deals made on Sunday. The SAMA’s intervention is attributed to the unavailability of certain vital information announced by a leading gas company because of the failure of the computer system.

The cancelled deals were made in the first quarter of an hour after the stock markets were opened for the morning session at 10 a.m. on Sunday.

However, the market operations continued without interruption from 12 noon till 1 p.m. when 329 new deals were made. The evening session worked normally.

According to an informed source SAMA cancelled the morning deals “because the sales and purchases were made in an unclear atmosphere and the customers were denied the opportunity to benefit from the announcements made by some companies as the computer systems were down.”

However the stockbrokers complained that because of the unexpected cancellation of the deals their clients suffered huge losses. SABIC shares which were sold at SR163 per share before the cancellation fell to SR158 when the market reopened at noon. The share prices of companies such as Saudi Cement, Yanbu Cement, Eastern Cement, Riyad Bank and Al-Baha Co. also were down when the market operations resumed.

The cancellation coincided with a meeting of the directors of tadawul (an electronic system to ensure fair and equal access to all share market participants in the Kingdom) in several local banks with SAMA’s systems officials.

In an official statement following the incident, SAMA said that the stock market operations have been resumed as usual. SAMA assured the dealers in the local stock market that it took all necessary steps to protect the rights of the investors and pointed out “even high-tech systems may develop some technical flaws.”

Even the share markets in London and New York have suffered system problems, the source said.

On Saturday the stock market operations were interrupted shortly after the beginning of the afternoon session. This also resulted in dealers missing the announcements of nine leading joint stock companies. The companies had announced their performance in the third quarter of the year between 3.01 p.m. and 3.57 p.m.

The market capitalization of the Saudi stock market stood at $70 billion at the end of 2000 making it the 12th largest market in the world. However, the top 10 firms divided among themselves 70 percent of the overall trade.