Booker to End Association With Start-Up He Founded

Mr. Booker’s association with the Internet firm, Waywire, had become an embarrassment for him even as he seems poised to capture the Senate seat in a special election next month.

Critics in both parties sharply questioned the prominent role he had played in forming the company, even while he was the full-time mayor of the state’s largest city — and one of its poorest.

Mr. Booker personally helped obtain money from influential investors — including Oprah Winfrey and Eric E. Schmidt, Google’s executive chairman — and tapped the expertise of technology moguls and entrepreneurs in Silicon Valley.

At one point, the firm became tabloid fodder when Andrew Zucker, the 15-year-old son of Jeff Zucker, president of CNN, resigned from a board that advised Waywire, a site whose goal includes making it easier to collect, curate and share videos from the Web.

In a statement, Mr. Booker’s campaign said on Friday that the mayor would be stepping down from Waywire’s board and donating his ownership interest in the company to charity. Mr. Booker, in a financial disclosure statement filed with the Senate, estimated that his interest in the company was worth $1 million to $5 million. But the company is said to be struggling.

“These steps are being taken to remove even the perception that the mayor’s attention would be diverted from his job as senator or that he would stand to personally benefit in any way from his holdings in the company,” the mayor’s campaign spokesman, Kevin Griffis, said in a statement.

Mr. Booker’s decision to sever his relationship with Waywire came on the same day that he released his tax returns for the last 15 years, showing substantial increases in income as he grew in prominence.

He earned a low of $40,797 in 1998, the year he went from being a community activist to waging a successful bid for a seat on the Municipal Council in Newark. Mr. Booker’s most lucrative year was 2011, when he reported that he received $715,981 in income and paid $221,760, or 33.6 percent, in taxes on the taxable portion of his income, according to his returns.

The income that year consisted almost entirely of his salary as mayor ($152,438), fees he earned for speeches he gave ($406,304) and payments he received from his old law firm for the sale of his stake in the firm ($150,000), according to the returns.

His income dropped significantly in 2012, when he earned $472,572 and paid $115,663, or 36.9 percent, in taxes on the taxable portion of his income. Once again, his earnings were largely from his salary as mayor, his speaking fees and payments from his law firm.

The Booker campaign, which had not released the returns for weeks despite repeated requests to do so, made them available to reporters for three hours on Friday at a conference room inside a hotel in Newark. The reporters were not permitted to make copies.

The returns answered questions that had been hanging over Mr. Booker, including the amount of money he received in payments from his former law firm, Trenk DiPasquale, for his stake after he left in 2006 to serve as mayor.

In all, he received so-called separation payments of $689,500, paid out in annual allotments from 2007 to 2012, according to the tax returns. He received the payments even as the law firm collected more than $2 million in fees from independent authorities, some of whose board members are appointed by the mayor, according to published reports.

Mr. Booker appears to be in a strong position to capture the Senate seat that became vacant with the death of Frank R. Lautenberg in June. After easily winning the Democratic nomination last month, Mr. Booker has emerged as a heavy favorite to win the October general election, in which his Republican opponent is Steven M. Lonegan, a former mayor of Bogota, N.J., and candidate for governor.

Nate Schweber contributed reporting.