The Federal Trade Commission yesterday accused Sunkist Growers, Inc., a large citrus cooperative, of monopolizing the western citrus fruit industry.

The complaint charges that Sunkist has achieved and maintained its monopoly - it markets 75 per cent of the total production of western oranges and lemons - by a variety of practices which restrained trade and injured its competitors:

Sunkist was accused of entering into exclusive dealing agreements with some 51 commercial citrus fruit packing houses under which they are not permitted to pack fruit for non-Sunkist members or deal with marketers or processors who compete with Sunkist.

It also was charged with entering into exclusive dealing contracts with 13 commercial packing houses connected with Blue Goose Growers, Inc., which foreclosed them from dealing with growers who were not members of Sunkist cooperative or with marketers of processors competing with Sunkist.

Sunkist allegedly withheld from the market a large supply of lemon products for the purpose or with the effect of stabilizing prices.

It allegedly has refused to sell western citrus fruit to competing processors and marketers.

The agency also charged that Sunkist's 1974 acquistion of Growers Citrus Products of Yuma, Ariz., a competing processor of citrus fruit, is illegal because it may lessen competition substantially or tend to create a monopoly.

Sunkist markets and processes western citrus and 51 commercial packing houses, the agency said. It sales totaled $482.9 million in the fiscal year ending Oct. 31, 1975.

Besides halting the alleged restrictive practices, the "notice of contemplated relief" attached to the complaint says that the commission also may seek to require that Sunkist sever all contracts with commerical packing houses, not enter into contracts with any additional packing houses for 10 years without prior FTC approval, divest itself of Grocers Citrus Products, and not acquire any citrust processing plant without prior approval of the FTC.

A complaint is brought by the FTC when it has "reason to believe" the law has been violated; Sunkist has 30 days to answer the charges which will be the subject of administrative hearing.

Attempts to reach Sunkist officials last night were unsuccessful.