The president of Pargas Inc. said yesterday that the company has retained a financial adviser to search for possible buyers for the company. The move is an apparent effort to head off a potential takeover by the wealthy and acquisitive Belzberg family of Canada.

N.L. Langley, president of the Waldorf, Md., marketer of liquefied petroleum gas, said that Kidder, Peabody & Co. had been hired "to investigate the possibility of an advantageous sale of the company, taking into consideration the best interests of its shareholders, employes and management."

The announcement followed a filing with the Securities and Exchange Commission by a firm controlled by the Belzbergs, revealing that the firm has acquired 9.9 percent of the outstanding shares of Pargas and is interested in taking over the firm.

It also followed several contentious days that began last Thursday when the Belzberg-controlled holding firm, First City Financial Corp., notified Pargas of its interest and was rebuffed.

According to records filed with the SEC, a Pargas representative indicated that the firm was willing to buy back the shares controlled by the Belzbergs for $36 a share, substantially higher than the price at which the stock traded during 1982. First City countered that it might be willing to entertain such an offer at approximately $40 a share.

Pargas Vice President and Treasurer Robert Harrison said yesterday that there has been no decision on whether Pargas will meet that price.

Pargas, founded in 1936 as Parlett Gas Co., distributes LPG and equipment for its use and storage. The company also has coal-mining subsidiaries and a Houston-based trading firm. Last September the company posted a record nine-month profit of $7.9 million ($1.90 a share) compared with $7.7 million ($1.85) in 1981.

The Belzberg brothers, Hyman, Samuel and William, started their financial empire in Western Canada and extended it across Canada and into the United States. They control assets worth more than $3 billion through First City Trust Co. and its controlling holding company, First City Financial Corp.

In 1981 the Belzbergs' aggressive efforts to exert more control over the Bache Group Inc. led Bache to seek out Prudential for a merger.

The Belzbergs recently acquired a large stake in Suburban Propane Gas Corp. of New Jersey but later sold their shares. The purchaser of those shares, National Distillers Corp., subsequently agreed to merge with Suburban. PARGAS PROFILE Shares outstanding--4,134,000 Revenue, nine months ending Sept. 30--$193,306 million Net income--$7.941 million Earnings per share--$1.90 Price per share--$28 at end of 1982; $35.87 yesterday Number of employes-2,000