LAST MONTH, while Congress was deciding how many commemorative coins the U.S. Mint should issue next year, one of the world's most successful mints was announcing its own new coin plans.

To many American collectors the new coins announced in Ottawa by the Royal Canadian Mint were more significant for what they signaled than for the subjects they honor. While officials at the U.S. Mint publicly have been dubious about their ability to market more than one commemorative coin set a year, the Canadians have been openly aggressive.

Their latest announcements illustrate that the same ambitious marketing strategy that made the Canadian Maple Leaf the world's best-selling gold coin will be pressed into use for other coins as well. The Canadian plans, no doubt, will give the three new congressionally mandated U.S. coins spirited competition next year.

In addition to a two-coin commemorative set honoring Canadian aviation, the Canadians have announced two other coin products aimed at the upscale end of the new coin market. They include a $200 gold coin, priced in the United States at $345, and a set of four platinum coins, priced at $1,760.

What makes both these sets interesting is that the Canadian mint is deliberately holding down its mintages in an effort to quickly sell the new coins and boost their subsequent resale in the secondary market.

"We're sensitive to the collector's desire to see his or her purchase appreciate over time," said Kristen Petersen, director of the Canadian Mint's collector coin programs.

That's something the U.S. Mint began experimenting with earlier this year, by limiting the mintages of its proof gold coins. The move has delighted many coin dealers who have complained that the large mintages ordered by Congress for many recent commemoratives have hurt the coins' long-range investment potential and have driven many collectors out of the new U.S. coin market.

Officials at the Royal Canadian Mint say they have heard similar complaints, but, unlike the U.S. Mint, they are seeking to expand their market by placing different themes on their coins.

And they are acknowledging that some of their coins are not for everyone.

"For sure, it's not everyone that can go out and collect all of these coins," said Michael Francis, communications manager for the Mint's bullion coins programs.

The Canadian platinum coins, for example, feature polar bear designs by Robert Bateman, one of the country's best known wildlife artists. Canada will produce only 3,500 sets of the four coins -- a one-ounce $300 coin, a 1/2-ounce $150 coin, a 1/4-ounce $75 coin and a 1/10-ounce $30 coin.

"The Polar Bear series is a luxury product designed specifically for the upsale market," said Murray Church, director of communications and research for the mint. "Our research tells us there is a niche for upsale collector items of the very finest quality, so we expect this to become the ultimate gift and collectors item. These coins will be popular here in Canada as well as Europe, where people are fascinated with Canadian heritage and wildlife."

There will be 25,000 of the $200 gold coins, the highest face value on a Canadian gold coin. These coins will feature a design by Ontario artist Stewart Sherwood showing a group of Canadian youths dashing in front of a map of the country bearing their flag. The gold coins contain about a half-ounce of gold.

By contrast, the U.S. Mint has pressed for a smaller number of coins, but always supported coins that will have wide appeal. Next year the smallest number of any commemoratives the U.S. will release will be the 500,000 $5 gold coins planned for the Mount Rushmore National Memorial Set. The set also will include up to 2.5 million silver dollars and 2.5 million clad half-dollars. In addition the Mint will be releasing 1 million silver dollars commemorating the Korean War and another million for the United Services Organization.

MINT OFFICIALS say the White House should resubmit the nomination of John Michael Mercanti, a sculptor/engraver at the U.S. Mint in Philadelphia, to become the Mint's chief sculptor/engraver early next year. President Bush nominated Mercanti this fall to replace Reagan administration appointee Elizabeth Jones, but the nomination died after the Senate failed to act on it before adjourning. Jones, the first woman to hold the office, had hoped to remain in the position, but failed to win Bush's support.

Mercanti, who joined the mint in 1974, has produced the designs for a number of the recent commemorative coins, including the obverse of next year's $5 gold Mount Rushmore coin and the dual portraits of Dwight D. Eisenhower on the silver dollar released this year to mark the centennial of the president's birth.

INFORMATION on Canada's coins is available from the Royal Canadian Mint, Box 457, Station A, Ottawa K1N 9H3, Canada, or call 800/267-1871.

Bill McAllister is a member of The Washington Post national staff.