Financially troubled TU International Inc. yesterday announced its third management shake-up in three months, amid staff layoffs of more than 50 people, or one-fifth of its work force.

Stepping down is Robert N. Verratti, a self-proclaimed specialist in corporate takeovers who replaced company founder David M. Owens as chairman in late October. The company, which is based in Falls Church, manufactures data-processing equipment.

Taking Verratti's place as chairman will be James L. Tarver Jr., who also serves as chairman and president of TU's largest shareholder, First Tarent Inc.

First Tarent, a 1-year-old Dallas-based company, purchased 80 percent of TU's stock last summer for $7 million in notes and property.

"Mr. Verratti had accomplished his goal in positioning the company to move forward with its operational and capital restructuring program," said First Tarent, a private holding company of 10 small firms whose businesses range from books to mobile-home manufacturing.

TU said it has retained the services of Dallas-based Michigan General Corp. "to assist in the development and implementation of the restructuring program." Michigan General is closely associated with First Tarent and has sold First Tarent several of the corporations it now holds.

TU has been faced with serious cash-flow problems for some time. Last summer, one of its subsidiaries, Dickenson Lines Inc., filed for protection from its creditors under Chapter 11 of the federal bankruptcy laws.

In the most recent documents filed at the Securities and Exchange Commission, TU's auditors said the company's working capital as of a year ago was "an area of extreme concern." They also noted that two other subsidiaries besides Dickenson were in default.

TU has not filed more current financial papers with the SEC, an omission that led the National Association of Security Dealers to drop the quotation of the company's stock trades from its over-the-counter listings.

When Verratti took over TU, he told the SEC in a separate filing that "the company's ability to continue as a going concern able to meet its obligations as they become due is highly dependent upon an immediate infusion of cash."

Company officials said yesterday that Verratti had obtained some funding, but apparently not enough to alleviate the cash-flow problems.

Given the magnitude of the problems, First Tarent decided to ask Michigan General -- a holding company with sales near $500 million -- to come in, officials said.

Company officials said the staff layoffs were one of the first steps taken as part of the restructuring.