The U.S. Naval Academy's former public works officer routinely solicited gifts, gratuities and Amway business from contractors who courted him in hopes of getting Navy construction contracts, a federal prosecutor told a jury as the trial of retired Capt. James Weston got under way in Baltimore.

But Weston's defense attorney told the U.S. District Court jury in opening statements yesterday that the captain "paid cash" for all the items the government says he received as illegal gratuities.

Weston, 48, of Henderson, Nev., went on trial on conspiracy, obstruction of justice and five bribery charges tied to his activities as the academy's public works officer from 1985 to 1989.

Prosecutors Jane F. Barrett and Richard Kay contend that Weston solicited such items as air conditioners, lawn mowers, a washer and dryer, and a rental car from Annapolis contractor Carroll Dunton in return for influencing lucrative academy construction contract awards.

"Why did [Weston] betray his training, his uniform, his fellow officers and, indeed, his country? Why did he abuse his position of trust? The answer is a simple five-letter word, greed," Barrett said in her opening statement.

Defense attorney William M. Ferris told the panel, "Much of what's going to decide this case is whether you believe James Weston or Carroll Dunton."

Dunton, an owner of Dunton Contracting Inc., is to be a key prosecution witness. He pleaded guilty last summer to giving illegal gratuities to Weston and to bribing Arthur G. Strissel Jr., the former Annapolis Housing Authority executive director convicted in 1988 of racketeering, bribery and wire fraud.

One focus of the government's case is a $961,333 contract for heating, ventilation and air-conditioning work at the academy's Rickover Hall classroom building in 1986, which Dunton's company won even though the Navy's estimate for the work was only $544,000.

Weston, who had authority to award contracts up to a $1 million, signed the contract papers.

But Ferris claimed that the project was approved by another Navy office and that Weston was asked to sign the papers fTC because the academy's resident construction officer did not have authority to award projects of more than $500,000. The lawyer said Weston had no authority to award or influence that contract.

Ferris also said Dunton used company money to buy items for Weston at good prices, and insisted that Weston repay him in cash.

The defense lawyer quoted Dunton as saying, "I like to play the ponies," and hinted that he pocketed the cash from Weston instead of returning it to his company.

Barrett charged, too, that Weston "pressured" other academy officers and staffers to buy Amway products from him and his wife, Mary, and later hid some documents involving those transactions from a federal grand jury that eventually indicted him.