In a move signaling even broad-based commodity ETFs will be affected by expected new limits on speculators, Barclays PLC (BCS) indicated it may stop issuing new shares for one of the most popular commodity investments.

In a regulatory filing dated Friday, Barclays said it would cease issuing new shares of the $1.6 billion iShares S&P GSCI Commodity Indexed Trust (GSG) when the total outstanding reached 55.9 million. It currently stands at about 52.5 million.

Other funds that have suspended issuing new shares, most notably U.S. Natural Gas ETF (UNG), have tended to trade at prices substantially exceeding the value of their holdings. Barclays appears to be the first company to say it would limit shares for a fund designed to track a broad basket of commodities, although Deutsche Bank AG (DB) said new restrictions could make it harder for one of its broad commodity ETFs to track its benchmark.

iShares S&P GSCI Commodity Indexed Trust recently changed hands at $31.25, up 62 cents, or 2%. The price amounted to a premium of about 1% on the value of its holdings.

-Ian Salisbury; Dow Jones Newswires; 212-416-2241; ian.salisbury@dowjones.com