NEWARK, N.J. — Prosecutors sought at a former Newark mayor’s corruption trial yesterday to show that he displayed a keen interest in the sale of city land.

Sharpe James is accused of abusing his office by steering nine city properties to businesswoman Tamika Riley, his co-defendant, who bought them for $46,000 and then quickly sold them for $665,000. Mr. James maintains that only the City Council had the power to authorize land sales. Prosecutors showed more than a dozen of Mr. James’s memos to the jury. None mentioned Ms. Riley, but most showed that Mr. James was closely monitoring whether developers he was familiar with were getting a chance to buy city lots.

Mr. James met routinely with developers in his City Hall office, his longtime personal secretary, Rose Marie Posella, testified. She couldn’t specify the frequency, but said: “It wasn’t on a regular daily basis.”

Some of the memos showed that Mr. James was interested in staying behind the scenes on some development matters. He instructed Ms. Posella to compose one memo on plain paper, not mayoral letterhead, while in another he directed his business administrator and two redevelopment officials to ensure he received a “blind carbon copy” of items they sent to the council on city land sales.

On Monday, Ms. Posella testified that Mr. Riley had privileged access to Mr. James, and that Ms. Posella and others in City Hall knew they were having an affair.