Special price reports from 250 firms in industries experiencing rapid price increases began to trickle in to the Council on Wage and Price Stability yesterday, but government officials said it was too soon to detect any price pattern.

In the meantime, two auto manufacturers announced they were raising their sticker prices. General Motors Corp. raised the price of its 1980 cars effective Tuesday by an average of $186, or 2.2 percent. The company said the price increase had been reviewed by administration officials.

Mazda, the Japanese automaker, said it will raise sticker prices by amounts ranging from $100 to $200.

Yesterday was the deadline for filing special price reports for the first 250 companies -- 150 oil companies and 100 other businesses in industries including air transportation, paper, cement, hotels, food processing, retailing and machinery. Since COWPS asked the 250 firms for the price reports it has asked an additional 430 firms from a variety of industries to file the same information.

The requests came during a time of growing administration concern that industries may be raising prices in an attempt to beat the imposition of wage and price controls, which many businesses expect.

In an attempt to head off those anticipatory increases, the Carter administration last week asked businesses to defer part of price increases scheduled for this week until next summer.

What triggered the request was a combination of events, said COWPS director R. Robert Russell. At the same time council analysts were hearing from a variety of sources in business that such price hikes were planned, they also saw evidence of widespread price increases in January and February consumer price indexes.

Not only did the CPI reports suggest that such price increases might already be taking place; they raised concerns that businesses might react to the news contained in the CPIs by raising prices.

"The ratcheting up of the rate of inflation fortifies the expectations of mandatory controls," said Russell.

COWPS analysts could not tell by looking at the CPI how much it reflected anticipatory price increases as opposed to businesses accounting for the costs of a slowdown in productivity. But the CPI showing, combined with informal reports suggested anticipatory price increases, he said.

"We have gotten some indications that my price increases in effect and a number announced as of April 1 are indeed to prevent getting caught with their bases (base prices) down if we should move to mandatory controls," said Russell.

GM's price hikes were expected to tough off an industry-wide round of automobile price hikes on 1980 models. GM is generally considered the industry's pricing leader.

GM Chairman Thomas A. Murphy said the price increase "only partially recovers" cost increased incurred by GM. Murphy said the GM price increases were within the Carter administration's guidelines.

Besides raising the prices of its 1980 model cars, Mazda Motors also raised it small car prices by $70 to $100.

Meanwhile, COWPS, which has 230 employes, said it would add 400 more primarily to increase its capacity to review price information from 2,900 companies with annual sales of more than $100 million. Unitl recently, COWPS has been monitoring data from 1,200 firms with sales of more than $250 million.