Mobil Corp. yesterday announced a major restructuring of its struggling Montgomery Ward & Co. Inc., a move financial analysts said was Mobil's first step in shedding Ward's, the nation's sixth-largest retailer.

In a brief announcement, Mobil said it plans to "build a new independent Ward's" that will be smaller, but stronger and more profitable, so it could survive on its own without any financial help from Mobil.

To spearhead the facelift, Mobil announced the appointment of Bernard F. Brennan, the president of Household Merchandising Inc., as Ward's next president. A highly respected merchandiser, Brennan served as Ward's executive vice president in 1982 and 1983, as Ward's was implementing a new merchandise policy to help the retailer break out of the red. Brennan fills a post that has been vacant ever since the first of the year when Stephen L. Pistner abruptly left the chain for another job at Rapid-American Corp.

"It is our intention to maximize Ward's value by reshaping it into a business which can operate as an independent, free-standing profitable retail company without Mobil ownership or financial guarantees," Mobil said.

One after another, financial analysts and retailing industry officials intrepreted that statement to mean that Mobil was getting ready to get rid of the 113-year-old retailer. The acquisition has caused headaches for Mobil, the nation's second-largest oil company, ever since it bought Wards nine years ago.

"They've made it clear they don't want to keep it -- that retailing is not in their plan," said John Landschulz of Mesirow & Co.

However, Mobil Vice President Herbert Schmertz said Mobil has not yet reached that conclusion. "We're not saying today that the company will be sold or divested," Schmertz said. When the company, which was restored to profitability only two years ago, becomes more profitable, "We will look at our options and decide what to do," he said. Those options include keeping Ward's, selling it or divesting it, he added. Mobil's decision will be based on "how to best maximize Mobil's shareholders' values," Schmertz added.

Schmertz declined to specify when Mobil planned to make its decision, saying only that the company is moving "with all deliberate speed" to restore Ward's financial health so it can make a decision.

"It looks like they are trying to build a more healthy company that would be sold more easily or spun off," said one industry expert who declined to be named. "That way Mobil would not look so bad to its stockholders, because it has already sunk a ton of money into Ward's."

Other analysts speculated that Mobil was upgrading the retail company because it has failed to find a buyer for the 322-store chain. They said they believed Mobil has been trying vigorously to sell it ever since Pistner left in January.

However, Mobil said that "at no time did we initiate or enter into negotiations to sell Ward's."

Mobil bought the Chicago-based retailer for $1 billion in 1976 to diversify from the oil business. The purchase came under attack in Congress, where members criticized Mobil for not spending its money on oil and gas exploration. Financial analysts subsequently joined the attack, criticizing the purchase after Mobil was forced to pour more than $600 million into Ward'ss to offset more than four years of losses.

Finally, in 1983, the company earned $40 million, and in 1984 it earned $53 million. "We want to significantly increase profit" even more, Schmertz said.

Mobil yesterday said it would incur more expenses in its restructuring of the company, writing off approximately $500 million after taxes to cover the costs.

Under the restructuring, Ward's will get rid of pieces of its retail, credit and insurance business "which cannot contribute to the profitability of a new Ward's. Ward's will be a smaller, more concentrated business," Mobil said, declining to be more specific about the pieces it wanted to shed.

Additionally, Mobil said "Ward's will eliminate the money-losing segments of its catalogue business."

Some of these steps were in the works before yesterday's announcement. Last January, Ward's announced that it was shutting down 300 of its 1,600 catalogue stores and laying off more than 1,200 employes nationwide. Last month, the company announced plans to lay off about 10 percent of its corporate staff of 6,500.

Brennan's appointment comes "at a critical time," Landschulz said. "Not having a top man in there since January was really getting to be a concern. The morale in retailing is extremely important, and it was starting to slip. People had lost enthusiasm and were really down."

Brennan -- the brother of Sears Roebuck & Co. President Edward A. Brennan -- "is a very good merchandiser, which is critical for the business," Landschulz said. Analysts say he left Ward's in 1983, after failing to get along with Pistner. However, they added, he was very highly regarded among the staff and viewed, before his departure, as Pistner's heir apparent.

Under Pistner, "Montgomery Ward has made a remarkable comeback already, improving its quality and presentation," Landschultz said. Among other things, the company redesigned the stores, cut 20 percent of its merchandise lines, abandoned unprofitable areas such as men's suits, carpeting and its labor-intensive installation departments, and added brand names to the hard goods it sold.

Ward's is converting some of its most profitable stores into an entirely new concept, where a single general-merchandise store would be turned into a series of specialty stores under one roof. Within a single store, seven separate stores are to be created to provide the best merchandise and service in automotive care, appliances, apparel, home furnishings, home improvements, home electronics, and recreation and leisure, according to company officials. The first such store is slated to be opened this summer in Annapolis, one of Ward's most profitable units.

Mobil said that Brennan's appointment should not change Ward's new store strategy.

The task of meeting Mobil's goals will not be easy, other analysts noted. For one thing, Ward's locations are not the best. "For years they have tried to snuggle up to other retailers -- which means they are not in mall spots but across the street from a mall. They do not have good enough real estate," a prime necessarity for a succesful retailer, noted Edward Weller of E. F. Hutton Group Inc.

Additionally, analysts note that Ward's upgrading comes as other retailers, including Sears and J. C. Penney Co., are in massive campaigns to improve their merchandise and image and as specialty stores are capturing a greater share of consumers' dollars.

"To turn around a company like Ward's will be a miracle job in an industry that is so competitive," said Louis W. Stern, executive director of the Marketing Science Institute.