Xerox Corp.'s proposed multibillion-dollar commercial and residential development in Loudoun County would provide 31,755 jobs by the time it is finished, the company said yesterday.

Plans for the project, to be built over a 10- to 15-year period on a 2,267-acre site about 10 miles north of Dulles International Airport, were submitted to the county government yesterday. Called Potomac Park, the project would be one of the largest developments in Northern Virginia.

Xerox said the development, which would require rezoning, would generate revenues of $309 million for Loudoun over the next 30 years, and cost the county about $116 million in services. Loudoun officials and politicians have said they are eager for the development, which they say would dramatically expand the county's tax base.

"I haven't met anybody yet opposed to it," said Frank Raflo, chairman of the Loudoun County Board. He called the public response to the Xerox proposal, announced last week, "overwhelmingly positive."

The 145-page proposal submitted to county officials also proposed housing for more than 6,100 people; two 400-room hotels, one including a large conference center; 10 to 13 major corporate headquarters and a dozen smaller office buildings; two golf courses and a town center of commercial establishments.

Xerox also proposed widening Leesburg Pike (Rte. 7) from four to six lanes on a one-mile stretch of the highway on which the project fronts. A Xerox spokesman said the road improvements would probably be financed in large part by private developers rather than by the firm itself.

County officials have said that the project, which is expected to generate heavy traffic along the already heavily traveled Rte. 7, must be accompanied by major road improvements.

Xerox also called for two major roads to loop inside Potomac Park, handling much of its traffic. The roads, to be known as Coton Parkway and Lee Parkway, would be divided highways, built to state standards and then given to the state road system, the firm said. There would be an interchange where the two loop roads would cross just north of Rte. 659, according to the Xerox plan.

The Xerox International Training Center is already located in the center of the site and would remain there under the proposal.

Nearly 1,100 acres would be preserved under the proposal, with building slated for the remaining acreage. Of the developed land, 575 acres would be for office buildings and 365 acres for residential neighborhoods. The rest of the developed land would be used for the resort hotel and conference center, the town center and the existing Xerox training center.

A statement prepared by Xerox called Potomac Park a "prestigious corporate . . . and residential community," and said housing prices would range from $100,000 for an apartment to $225,000 for single-family houses.

The project, which although under Xerox control would be financed in large part by private investors, would be developed in five stages, the company said.

The initial phase, scheduled to begin next year, would include nearly 2 million square feet of office space as well as a 400-room resort hotel, which would include a golf course and athletic center.

Although there would be some residential construction in the initial phase, Xerox officials said the emphasis at the outset would be on corporate and commercial development, which they consider a more certain economic bet in the short term.

All the Xerox land is currently zoned for agricultural and rural residential use. Xerox is seeking a rezoning that would allow both office parks and housing developments.

The Loudoun board must approve the zoning changes if the plan is to proceed.