The Seattle SuperSonics made their third major trade of the season Wednesday, acquiring center Benoit Benjamin from the Los Angeles Clippers for backup center Olden Polynice and two draft choices.

The exchange of 7-foot centers was made a day after Benjamin said he intended to test the free-agent market after the season as an unrestricted free agent and a day before the NBA trading deadline.The Sonics acknowledged the trade was a gamble.

"Absolutely, this is a major risk," Sonics president Bob Whitsitt said in a telephone interview from New York. "Next summer, Benoit can sign with anybody he wants to.

"So it's going to make for a challenging summer. We're committed to trying to sign Benoit. We're going out on a limb but we believe it's a limb worth going out on."

Benjamin, 26, is in his sixth NBA season. He was the third player selected in the 1985 NBA draft after playing at Creighton for three years.

The 260-pound Benjamin is averaging 14.9 points, 12 rebounds and 2.33 blocked shots in 39 games. He missed 11 games - eight because of oral surgery and three because of a separated shoulder.

Before this year, Benjamin played in 367 NBA games and averaged 13.1 points, 8.4 rebounds and 2.8 blocked shots.

Polynice is in his fourth NBA season. He was the eighth overall selection of the 1987 NBA draft by the Chicago Bulls, but was traded to Seattle before the 1987-88 season began.

Polynice, who attended Virginia, has played in 48 games as a reserve for the Sonics this season, and is averaging 8.3 points and 5.6 rebounds. In his first three NBA seasons, Polynice averaged 3.9 points and 3.5 rebounds.

Benjamin is expected to become the Sonics' starting center ahead of 6-9 Michael Cage, who has been playing at center although his natural position is power forward.

"When the Clippers made their decision that they might trade Benoit, we looked at all the centers who weren't available."

As part of the deal, the Clippers receive Seattle's first-round draft choices this year and in either 1993 or 1994. There are no restrictions on the trade, meaning the Clippers get Polynice and the first-round draft choices regardless of whether Benjamin signs a contract with the Sonics after the season.