With oil prices down to less than $29 a barrel and natural gas prices stabilizing after five years of sharp increases, Americans seem to be losing some of their zeal for conserving energy, according to newly released government figures.

A report by the Energy Information Administration says per-capita U.S. energy consumption dropped only 2.4 percent in 1983, compared with annual declines of 4 to 7 percent in the previous three years.

The report was issued as the Organization of Petroleum Exporting Countries concluded an emergency meeting in Geneva, where the cartel made cosmetic cuts in oil production in an effort to prop up their posted price of $29 a barrel against discounts of $1.50 to $2 discounts offered by many producers.

Energy Secretary Donald P. Hodel expressed doubts in a statement that OPEC's action will affect world oil prices.

"Trying to manipulate the market by setting artificially high prices or by seeking to fashion arbitrary restrictions on production is not in the interests of U.S. and other consumers or, in the long run, of producers," he said.

"The market has sent a clear signal that the current world oil price is too high in relation to demand and should come down."

The report said Americans are using an average of 21 percent less energy than a decade ago.