Assistant Treasury Secretary C. Fred Bergsten said yesterday the United States had "good success" during a recent Mideast trip of Secretary W. Michael Blumenthal, in urging oil-producing nations to limit their price increase when they meet next month.

Bergensten, who accompanied Blumenthal, did not provide any details but he said the U.S. is still hoping for a moderate price increase.

A Kuwait newspaper, meanwhile, reported that members of the Organization of Petroleum Exporting Countries (OPEC) have agreed to raise the price of oil by 8 percent during 1979-in quarterly increments of 2 percent.

The daily A1 Watan said the increase will be adopted formally during the regular six-month OPEC meeting in Abu Dhabi, Dec. 16. The staggered increase appeared to be a compromise between Saudi Arabia, favoring either a freeze or a minimum increase, and Iraq and Kuwait, which supported a hike of at least 10 percent immediately.

While Gergsten said yesterday it would be "desirable to have a freeze" on oil prices he added that it probably wasn't "realistic to expect it."

Kuwait oil minister Sheikh Ali Khalifa as Sabah and United Arab Emirates minister Maneh Said Al Otaiba consider an oil price hike "taken for granted and unavoidable in order to compensate OPEC members for losses resulting from the dollar's decline," Kuwait government sources said.

Obtaiba conferred with Khalifa on efforts to reach a price hike for 1979 "that would preserve OPEC unity and represent a compromise between hardline and moderate member countries," the sources said.

In Libya, oil secretary Ezzedine al Mabrouk said oil producers must raise their prices next year because of the erosion of their income due to the decline of the U.S. dollar and inflation, according to an interview published yesterday.