And now, from the wonderful people who brought you Bloomingdales, comes a store for Washington consumers who want a little "better" place in which to shop - I. Magnin.

What? Better than Bloomingdales? More upscale than the department store that practically invented upscale merchandising? More elitist than the East Side of Manhattan? More expensive than the store that gets $4.50 a pound for chocolate chip cookies and $3 for ordinary cotton underpants with the store's nickname on the backside?

Yes, acknowledge I. Magnin merchants, they intend to be all of those things - more expensive, more elitist, more upscale and "better" than their corporate cousins at Bloomingdales in the retailing sense of the word, where better means higher-priced.

The Magnin store that opened Friday at the White Flint shopping mall is the vehicle that Federated Department Stores is counting on to expand its hsare of the Washington market.

A $4.9 billion merchandising machine that earned $197 million profits last year, Federated is the parent of Magnin's, Bloomies and 16 other retail chains that operate 223 department stores, plus 100 supermarkets, a handful of discount stores and a hardgoods specialty chain.

The same consumer profperity and propensity to spend that brought Bloomingdales from New York to Washington - and White Flint - drew Magnin's from California, Magnin President Ross Anderson said in an interview last week.

Federated's department store companies are "largely autonomous," the company says in reports to stockholders, and Anderson said it was Magnin officers rather than Federated executives who initiated construction in Washington of Magnin's 24th Store.

Federated has two divisions in several West Coast markets, where there are Magnin and Bullock's stores. In those cities, as in Washington, Magnin and its corporate cousins "complement each other more than compete," explained Anderson.

"We carry more status merchandise than Bloomingdales, or almost anyone else, for that matter," said Anderson. "We really think that we have two competitors nationally: Neiman-Marcus and Saks Fifth Avenue."

Saks and I. Magnin do not always compete, the Justice Department charged in a complaint accusing the two chains of fixing the prices of women's clothing in Northern California. Magnin paid a $50,000 fine and the case was closed earlier this year.

Women's clothing is the mainstay of Magnin's business, although Anderson prefers the term "feminine" because women's, in retail language, usually refers to the department catering to older, more connservative customers, who are by no means the mainstay of the Magnin image.

"We really have two kinds of customers," Anderson said, using words that could just as easily have come from his competitors, "those who have arrived, or whose husband has arrived, and those who are not yet to that point, but expect to be."

The Magnin president describes his clients as "sophisticated" and when asked if they are "hipper" than Saks or Neiman shoppers replied, "Hipper would not apply to us." Nor is there any attempt by Magnin buyers to match Bloomingdales' reputation for being trendy.

Anderson said the store will carry more designer merchandise "than Bloomingdales or anyone else in town," and cited dresses as an example of magnin's merchandising strength. Between $125 and $250, "we can out-assort most anybody," he said.

In men's wear, Magnin is not so strong, Anderson acknowledged.

Federated doesn't reveal sales figures for any of its operating divisions or its individual stores. Annual sales of $100 per square foot of selling space - a traditional target of big stores - would be considered a minimum for the White Flint Magnin store, executives hinted. Other retail sources estimate that the 81,000-square-foot store, which Magnin said cost $10 million to build and stock, ought to do $12 million to $15 million a year.

The success of the store in Northern Virginia and a third in downtown Washington "would be the ideal situation," Anderson said. "We'd like to have a headquarters store downtown; it depends on how downtown develops," he added. Magnin has been mentioned as a potential tenant in two Fairfax County malls that are on the drawing board - Tysons II at Tyson's Corner and the Taubman Company center near the intersections of Interstate 66 and Route 50 - and is a target of developers of several downtown proposals.

The White Flint I. Magnin is one of 14 stores that Federated has said its various divisions will build this year, adding 2.5 million square feet of selling space to the corporation's acres of stores.

The Cincinnati-based Federated's other department stores around the country are Abraham & Straus, The Boston Store, Bullocks, Burdines, Filenes, Lazarus, Goldsmith, Shillitos, Rikes, Sanger Harris and Rich's. There are also two discount store divisions - ZGold Circle in Ohio and Richway a spin-off of Rich's department stores in Atlanta; Gold Triangle, a Florida hard goods specialty store that is a cross between hechinger's and Heman's, and Ralphs supermarkets, the number one food chain in the Los Angeles market.

Last year the company grew by 25 stores - including the White Flint Bloomingdales - adding about 2.9 million feet of space, and helping boost sales by 10.7 percent, from $4.4 billion to $4.9 million. About 4.5 percent of that sales gain resulted from inflation, the rest from new stores and sales increases, the company estimates.

Federated has expanded agressively in the past five years, moving into 19 new markets (for a total of 57). That expansion has brought the various Federated stores within shopping distance of another 18 million persons, with the potential for generating $22 billion in sales, Federated says.

In the past year, Federated's earnings increased faster than sales - due largely to controls which kept the growth in expenses below the growth in sales - producing a 16.9 percent gain in earnings for the fiscal year ended Jan. 31. Profits for the year were $197 million ($4.09 a share), up from $168 million ($3.50) in 1977, leading Federated's board to increase the company's annual dividend from 36.5 cents a share per quarter to 40 cents.

The business philosophy producing those profits is summarized by a Federated executive quoted in the company's latest annual report: "Department stores are diversions, not just places where people go to buy the necessities of life."