The New York Commodity Exchange terminated the liquidation-only restrictions on silver futures contracts yesterday and partially opened the market to new participants, effective Thursday.

The Comex directors said new investors can take net positions in 400 contracts in all months, including the nearest. In the spot months and next month, gross positions are limited to 100 contracts in each.

The Comex, citing what it claimed was a physical shortage of silver, had used its emergency powers to limit trading in silver to liquidation.

On commodity markets yesterday, speculation that the U.S. hostages in Iran will be released soon and a strong stock market dampened enthusiasm for buying precious metals futures, commodities that skyrocketed as world tensions increased.

Often soft commodities like sugar and cocoa, meanwhile, continued to find speculative support despite world news developments to push prices to the daily trading limit in some months.

Gold futures gained $9.50 to $10.70 an ounce on New York's Commodity Exchange Inc., closing at $688 for February-delivery contracts.

Platinum futures on the New York Mercantile Exchange dropped $9 to $20 to close at $900 an ounce for the spot contract month.

Copper futures, though, continued their upward price climb charting slight gains despite a bout of profit-taking by commission houses and local traders after a run-up Tuesday that saw new record highs established.

Sugar futures were locked up the daily trading limit for most of the day, so speculators eager for trade moved into the cocoa market, which had been weak prior to the new interest.