The D.C. Commission on Baseball officially announced yesterday that it will begin a campaign to sell as many as 10,000 tickets for a nonexistent team.

Mayor Marion Barry said this would "demonstrate to the baseball community what we already know: that the Washington, D.C., area is a big sports town." Virginia Gov. Charles Robb and several Maryland public officials attended the press conference at RFK Stadium.

Commission chairman Frank Smith, a D.C. councilman, said prospective ticket holders could choose from among three packages: an 81-game plan for $567, a 27-game plan for $189 and a 10-game plan for $70.

Smith said that 16 banks in the District, Maryland and Virginia will begin accepting deposits on April 17; deposits of more than $1,000 would be placed in a money market account, while deposits of less than $1,000 would be placed in a savings account.

If the District should fail to acquire a team within two years, Smith said, the money, plus interest, would be returned to the depositor. If a team is secured, the money would be turned over to the new owner.

"We're really not asking people to take much risk," Barry said. "The commission's goal of selling 10,000 season tickets is just the first step toward showing that our city is serious about bidding for a professional baseball team to come to Washington."

Morris Siegel, a consultant to the commission, said more than 16,000 individuals and businesses have pledged support to buy either season tickets or combination packages.

Meanwhile, baseball Commissioner Peter Ueberroth, speaking from Cincinnati, reiterated what he had told The Washington Post in a March 1 interview: that he doesn't consider any United States city suitable at present as a site for an expansion baseball franchise.

"I only favor expansion when there's a city that qualifies under three criteria: local ownership with roots in the community, great fans and support of the city, county and state and their politicians. There are no such cities that qualify now," the Associated Press quoted Ueberroth as saying.

Asked to comment on Ueberroth's statement, Smith said, "Let me put it this way, Washington might not be there yet, but we're close" . . .

The following banks have agreed to accept deposits for ticket purchases, beginning on April 17:

In the District: Riggs National Bank, American Security, First American, the National Bank of Washington, the National Savings and Trust and the D.C. National Bank.

In Virginia: First Virginia Bank, Sovran Bank and Bank of Virginia.

In Maryland: First American Bank of Maryland, First National Bank, Union Trust, Maryland National Bank, Heritage Bank, Suburban Bank and Columbia First.