Bruce Ratner acknowledged yesterday that he wasn’t prepared to take over as the New Jersey Nets’ owner last summer because he was more focused on making a profit than doing what was best for the team and re-signing power forward Kenyon Martin.

“Last year, we started looking at the money instead of what the team needed,” Ratner said. “Now, it’s the other way around.”

Speaking with beat reporters, Ratner touched on a wide range of topics, including the team’s planned new arena, club finances, the future of the Nets’ Big Three, and input from All-Star Jason Kidd.

Ratner said his planned new arena in Brooklyn won’t be ready until at least the 2008-09 season, with a groundbreaking expected sometime next year.

He acknowledged that reports that the team lost $30 million this past season were relatively accurate.

After being swept in the first round of the playoffs, Ratner said he would be surprised if the team traded any one of its big stars – Kidd, Vince Carter, and Richard Jefferson.

And he had no problem with Kidd putting pressure on management to make the team better, adding he would be willing to listen to any suggestions the point guard had to make.

Heading into his second off-season, Ratner said much has changed since the Nets were forced to sign and trade Martin to the Denver Nuggets rather than match an offer that the Brooklyn real estate developer felt was too costly.

After paying roughly $300 million to buy the team, Ratner said his first mistake was to try to draw up a budget for the 2004-05 season.

“You can’t do that,” Ratner said. “You have to look at what you have.”

The restrictions of a budget also led Nets president Rod Thorn to trade guard Kerry Kittles to the Los Angeles Clippers for a second-round draft choice and to release well-liked backup shooting guard Lucious Harris.

The moves not only weakened a team that went to the NBA Finals in 2002 and ’03, but they annoyed Kidd to no end and led to problems that lasted for months.

“I wasn’t ready to be an owner,” Ratner said. “I never anticipated that some of the other co-owners might have a large role. It’s funny because [NBA Commissioner] David Stern said you could have only one person in charge. I heard it but never processed it.”

Ratner said there were too many people involved in making decisions last summer.

“You can’t run a business like that and you can’t run a sports team that way,” Ratner said.

Ratner is now the final voice on all decisions involving the team, although he said he is leaving most of the basketball decisions to Thorn and General Manager Ed Stefanski.

He also wants Kidd to be happy.

“We share the same goals, which is winning,” Ratner said. “We share the same goals, which is getting players to make us an even better team. I don’t think there is a conflict. I don’t see a problem with Jason pushing management. That’s fine.”

Ratner conceded that he and Kidd were not on the same page last year.

“I take responsibility for last summer,” Ratner said.