By Grant McCool

NEW YORK (Reuters) - Prosecutors over-simplified an insider trading case against former technology consultant Winifred Jiau, and a lack of trades by hedge funds on her tips belied accusations she was central to a brazen scheme, Jiau's lawyer told a jury on Thursday.

The lawyer, Joanna Hendon, said in closing arguments at Jiau's two-week-long trial that the evidence showed there was reasonable doubt that advance earnings figures she had about chipmakers Nvidia Corp and Marvell Technology Group Ltd in 2008 were material.

A federal prosecutor told the New York jury in his summation earlier on Thursday that Jiau cultivated friends as "spies" at the companies to provide financial secrets she shared with hedge funds in exchange for checks totaling more than $200,000 in two years.

Recorded phone calls, instant messages and emails showed Jiau used code language to try to hide wrongdoing, Assistant U.S. Attorney Avi Weitzman said. Jiau referred to her two sources as "cooks," to money as "sugar," and confidential information as "recipes,"

But defense lawyer Hendon said co-conspirator Samir Barai of Barai Capital Management relied on various sources of information about Marvell and made just one trade on May 29, 2008, that could have been based on Jiau's information on quarterly results.

The defense lawyer said that aspect of the government's case was "wall-papered, plastered with reasonable doubt about what Mr Barai is relying on."

She argued that there was evidence Barai -- who has pleaded guilty to criminal charges -- used other sources and spent time and money researching the company and its prospects.

"In the real world, it is much more complicated," Hendon said. "It is an over-simplification that's being presented and it is belied by the lack of trading in the record."

Taiwan-born Jiau, 43, has pleaded not guilty to charges of conspiracy and securities fraud. She is the only person to go on trial so far among more than a dozen charged in a U.S. probe of so-called expert network firms, which match business experts with investment managers looking to better understand various industries.

The government says that some expert networking employees have trafficked in confidential, inside data such as upcoming corporate earnings figures that could give money managers an edge if they traded on the information.

Weitzman told jurors, who will begin deliberations on Friday, that Jiau "cultivated colleagues and their friends and pumped them for information.

"With these well-placed insiders at Nvidia and Marvell, Winifred Jiau had spies in those companies."

Jiau has been denied bail since her arrest in December at her house in Fremont, California, where she lived alone with her dog, Hunter. If convicted, Jiau faces up to 25 years in prison.

The government said Jiau, who worked as a consultant for the Primary Global Research expert networking firm, received checks totaling $208,000 over two years after she gave hedge fund managers precise earnings information on chipmakers Nvidia and Marvell in 2008 before public announcements.

Jiau also traded on inside information, according to prosecution evidence.

Prosecutors said the "well-placed insiders" whom Jiau cultivated were former research analyst Sonny Nguyen at Nvidia and accountant Stanley Ng at Marvell.

Vietnam-born Nguyen, 39, pleaded guilty to charges and testified against Jiau.

Trial records show Ng was put on leave by Marvell in January after he declined to cooperate with an internal investigation.

Ng could not be reached to comment. Marvell spokesmen did not return calls for comment.

At least 10 other defendants have pleaded guilty to criminal charges in the case, including consultants and two hedge fund managers who said they received tips from Jiau and arranged her fees -- Barai and former SAC Capital hedge fund manager Noah Freeman.

The case is USA v Winifred Jiau et al, U.S. District Court for the Southern District of New York, No. 11-00161.

(Editing by Steve Orlofsky, Gary Hill)