Democratic mayoral candidate Patricia Roberts Harris unveiled yesterday her campaign's major proposals for economic development, including creation of a semiprivate corporation that would provide millions of dollars' worth of loans, subsidies and below-market city land to encourage D.C. businesses to expand and hire additional employes.

Modeled after nonprofit development agencies in Baltimore and Philadelphia, the proposed "D.C. Corporation for Economic Development" would focus on rejuvenating inner-city retail and commercial areas -- such as those along H Street NE, 14th Street NW, New York Avenue NE and Georgia Avenue NW--and stemming the flight of businesses to the suburbs.

Harris, who spoke to reporters in a vacant lot near Ninth and H streets NE, also promised to step up the job-placement activities of the D.C. Department of Employment Services and to tailor job-training programs to fill existing jobs.

She claimed that Mayor Marion Barry has placed too much emphasis on his summer youth employment program and not enough on employing adults. In June, the city's overall unemployment rate rose to 11.3 percent or about 35,600 people.

"I intend to treat joblessness in this city as the emergency that it is," said Harris, shown in polls and campaign fund-raising totals as the leading Democratic challenger to Barry in the Sept. 14 mayoral primary. "I will not be satisifed with a jobs program that only concentrates on youth during the summer."

When asked by a reporter how many jobs she planned to create as mayor, Harris replied: "The creation of jobs takes time, but I would hope to place 32,000 as soon as possible." An aide later said that Harris may have been engaging in a bit of campaign hyperbole.

Harris released a 35-page statement, entitled "A War for Economic Survival," that offered the most detailed explanation to date of how she would attempt to combat unemployment and stimulate business growth.

The city would sell or lease choice parcels of city-owned surplus land, often at below-market costs, to encourage businesses to expand and to attract light industry to the city, under Harris' plan.

"The land bank would be used, not as District land has been in recent years simply as a means to dispose of property, but as part of an overall strategy . . . " Harris said.

Harris said she would double the $2.5 million in federal community development block grant funds the city currently earmarks annually for economic development. She also promised to increase greatly the city's budget for job-training programs, even if that means cutting other services.

Harris declined to estimate the total cost of her proposed initiatives, including establishing and operating the new development corporation.

The six-year-old Baltimore Economic Development Corporation, which is similar to the agency Harris envisions, has a staff of 14 employes and an annual operating budget of $700,000, according to senior vice president David Hash. Last year, the Baltimore corporation helped finance $170 million worth of expansion by 75 companies that saved 4,650 jobs and created 2,850 others, Hash said.

The D.C. corporation would be supervised by a board of directors that would include city officials, business people and community leaders. The agency would be able to hire its own staff, outside of civil service, to assist business and community groups in assembling development packages and arranging for public or private financing.

Harris said yesterday that the new corporation would take under its wing funds and programs already administered by city agencies, including federal block grants and action grants, federal funds for job training, federal loan guarantees and industrial and commercial revenue bonds issued by the D.C. government.

Ivanhoe Donaldson, Barry's campaign manager, said yesterday that city agencies and boards already were involved in many of the economic development activities that would be handled by the corporation proposed by Harris.

"I truly doubt Mrs. Harris is recommending anything that doesn't already exist in another form," Donaldson said.

"I'm sure there are ways to do it better and more efficiently, and as we move along we try to do it better and more efficiently," he added. "It's not an overnight thing. It takes time."