JERSEY CITY,N.J.— Senator Corzine’s wealth was supposed to be his ticket to the New Jersey governor’s office.

But his riches raised eyebrows around the region yesterday as the Democrat found himself defending a $470,000 gift to an ex-girlfriend who runs one of New Jersey’s largest state employee unions.

The money — originally a mortgage loan until Mr. Corzine canceled the debt — merely scratches the surface of the candidate’s personal fortune, estimated at more than $260 million. But it allowed Carla Katz, president of Local 1034 of the Communications Workers of America,to buy out her ex-husband’s share of a 19th-century home and 10-acre property in Alexandria Township, Hunterdon County.

Yesterday, Mr. Corzine said the loan would not hamper his administration’s ability to negotiate fairly or effectively with the union, which represents 16,000 public employees, even as the Republicans were crying foul.

Mr. Corzine’s opponent in the governor’s race, businessman Doug Forrester, said the gift to Ms. Katz “suggests an all-too-familiar pattern in New Jersey of public officials entangling themselves in relationships that are not private matters but in direct conflict with the public interest.”

Mr. Corzine’s involvement with the labor leader is significant because the CWA is one of a handful of unions expected to press the state for billions of dollars in wage increases and pension and health fund bailouts. Mr. Corzine could find himself on the opposite side during negotiations — representing the state — should he defeat Mr. Forrester in the November election. The current CWA contracts expire June 30, 2007.

“The governor doesn’t do the negotiating; he has to sign off on it,” Mr. Corzine, 58, said. “It’s a very transparent process. It doesn’t put me in an awkward position, because I represent the people.”

Labor lawyer Albert Kroll, who served as state Labor commissioner under the former governor, James McGreevey, agreed.

“The governor plays very little role with respect to negotiations with state employees,” Mr. Kroll, who was on staff when the state negotiated its most recent contracts two years ago, said .

“If you look at the collective bargaining agreement that started in 2003, there is a parity clause so that everybody (every union) has the same wage increases, the same benefits, et cetera. If you start to treat one differently, you have big problems,” Mr. Kroll said.

According to documents filed in Hunterdon County, Mr. Corzine turned the 10-year mortgage into a gift to Ms. Katz last December, a week after kicking off his campaign for governor and several months after the two stopped dating in July.

Mr. Corzine said he forgave the loan from JSC Investments LLC, a company he owns, because Ms. Katz did not have the means to repay it. Mr.Corzine said he took care of the gift tax on the money.

The CWA endorsed Mr.Corzine’s Senate candidacy five years ago and recently endorsed him in the governor’s race, one of only two in the nation this year. Mr. Corzine spent $63 million of his own money to win a U.S. Senate seat in 2000.

A former CEO of Goldman Sachs, Mr. Corzine met Ms. Katz in 1999 when he was campaigning for Senate run. He split from his wife of 33 years in 2002, and their divorce became final in late 2003. Ms. Katz, 46, who has two children, was divorced from her husband in November 2001, court records show.

Mr. Corzine, who has a double-digit lead over Mr. Forrester in recent polls, said that when he made the loan he was not considering running.

“I’m a public official, but I also have a private life. I had a serious relationship with Carla that ended, but certainly at the time when that mortgage was let, it was serious, and at the time I thought I had the possibility of being in a long-term relationship,” Mr. Corzine said. “The people will have to decide whether public officials can have private lives,” he said yesterday.

Ms. Katz did not return phone calls or an e-mail message seeking comment yesterday. In interviews with the New York Times and the Star-Ledger of Newark, she said she was confident the matter would not compromise her constituents in negotiations. She said she and Mr. Corzine remain “great friends.”

Mr. Corzine’s relationship with Ms. Katz, widely known in political circles, drew fire from Republicans, who linked the loan to last year’s bombshell announcement from Mr. McGreevey that he was gay and had an affair with a man. Mr. McGreevey resigned after acknowledging an affair with a man his staff identified as Golan Cipel, Mr. McGreevey’s former homeland security adviser. Mr. Cipel has denied the claims.

“It’s more than ironic that a year ago Jim McGreevey announced his resignation because he wouldn’t let somebody who had personal knowledge about him compromise his ability to do the right thing for the people who elected him,” Republican State Committee Chairman Tom Wilson, said.”A year later, we can substitute the name Jon Corzine for Jim McGreevey and the name Carla Katz for Golan Cipel.”

Democratic strategist Rick Thigpen had a different view.

“If he can foresee paying the gift tax on that money, he can certainly foresee the need to have nothing but an arm’s length relationship with her union as governor.”