The Prince George's County Council voted yesterday to divide the sprawling county into two cable television franchise areas, the first step in bringing cable service to the county's approximately 700,000 residents.

Using Central Avenue as a general boundary, the council created northern and southern franchises. It also specified within each franchise a smaller, more densely populated area that first will receive cable services once the council selects the one or two companies to supply such service in the county sometime next year.

In the meantime, the cable map will be used by the county's cable television commission to solicit bids from the 30 or so cable companies that have expressed an interest in the county's cable franchises, which promise annual profits of $9 million to $12 million.

In addition to the county-wide franchises, Prince George's 28 municipalities have the option of setting up their own cable systems or affiliating with the county. So far, only six municipalities have decided to go on their own.

Laurie Early, acting executive director of the cable commission, said yesterday that she expects the commission to send out a request for proposals to all interested companies in the fall. The companies then will have 90 days to submit their bids and specify the rates they will charge subscribers, number of channels and services they will offer, and the speed with which they will build a cable system.

After that, the commission will evaluate the applications and forward them to the County Council. The final selection process, which could begin by next spring, is expected to be a highly political affair because of the large stakes and prominent personalities involved.

Among the 30 or so companies that have so far expressed an interest are several that are represented locally by friends and political associates of both the all-Democratic council and the Republican county executive, Lawrence Hogan.

Among the more familiar names associated with the cable companies are those of former county executive Winfield M. Kelly Jr., a Democrat who still maintains close ties to many council members, Democrat Del. Frank Komenda, and Gerard Holcomb and Charles Dukes, longtime confidantes of Hogan.

Hogan and the council have traded charges of politicking over the choice of an outside consultant for the commission, the council's vote to dilute the powers of the Hogan-appointed commission and the selection of cable companies by municipalities.

Hogan has charged that the council automatically will vote to give the franchise to Storer Cable, the company Kelly represents in Prince George's and the entire Washington area. The council has responded that it will make its decision on the companies' qualifications, financial backing and services.

Early said she expects most of the cable companies to bid on both the north and south franchises as well as submit a proposal for a county-wide system.

The division approved by the council yesterday places approximately 123,200 households or 355,800 people in the northern franchise and 106,000 households or 312,700 people in the southern franchise.

In the northern franchise the section to be built first includes Laurel, Bowie, Beltsville, Langley Park, Chillum and Landover Hills. In the southern franchise, the first section built will include Oxon Hill, Camp Springs, Clinton, Palmer Park and Forrestville.

According to county codes, both franchises are to be completed within five years of the date on which the council makes the cable award. In some rural areas of the county, primarily in the southeast section toward Eagle Harbor, cable companies will not be required to build cable lines because of "economic infeasibility," Early said.