Copper prices should average around 115 cents per pound (US$2,535 a metric ton) in 1990, and any change is likely to be on the upside, analyst Shearson Lehman Hutton said Tuesday.

In its "Annual Review of the World Copper Industry, 1990," Shearson said copper is likely to move into marginal oversupply over the next two years.Prices will average around 115 cents per pound in 1990 before falling back to 95 cents in 1991, Shearson said.

However, Shearson said, copper stocks will remain low by historical standards and suggested "serious dislocation to supplies" could lead to ''new highs for copper."

Shearson said while copper had the potential to move into oversupply in 1988 and 1989, the outcome was different.

Output was hit by supply problems and delays in capacity additions, and demand remained strong. Hence copper moved into 1990 with stocks still at ''chronically low levels," the analyst said.

In addition, increases in stocks are expected to be modest over the next two years.

Shearson estimated primary refined copper production in the non- Socialist world to rise to 7,235 million tons in 1990.

With the addition of secondary refined production of 1,400 million tons and imports of 260 million from the Socialist nations, total refined copper supply is expected to reach 8,875 million, it said.

With total refined demand for copper seen at 8,735 million tons, Shearson predicted stocks will rise by 140,000 tons in 1990. A further increase of 90,000 tons is expected in 1991.

However, Shearson indicated that despite the rises, stocks will be modest by historical standards. Commercial copper stocks would remain below five weeks of consumption at the end of 1991, compared with levels of over 12 weeks in 1982 and 1983, the analyst said.

It also expects steady growth in copper consumption. Although lower demand was predicted for North America, rising consumption elsewhere should lead to overall growth of 0.9 percent in non-Socialist world copper consumption during 1990, Shearson said.

Copper consumption in North America is expected to fall by 3.5 percent in 1990, but is expected to rise by 2.1 percent in Japan, 1.0 percent in Europe, and 4.1 percent in non-industrialized nations.

Overall, non-Socialist world copper consumption is expected to reach 8.615 million tons in 1990, and should rise a further 2.4 percent to 8.825 million tons in 1991, Shearson said.

Shearson also predicted copper demand in non-industrialized nations to continue to grow. Copper consumption in non-industrialized nations made up 17.8 percent of the world total in 1989, whereas in 1979 it was 11 percent.