Positive Changes Seen at AST Research : Manufacturing: Three promotions are a sign the Irvine computer firm is getting back on track, analysts say.

Continuing its long management restructuring, computer maker AST Research Inc. named two managers to slots as vice presidents and promoted another to marketing director in moves it hopes will solidify its operations.

Analysts said the internal appointments are a sign that AST, shaken by losses from manufacturing problems and delays, may be getting back on track, particularly after three vice presidents involved in production left the company last year.

AST’s top management, meantime, is working to complete a stock transfer that would give giant Samsung Electronics Co. in South Korea a 40% stake.

Management also is trying to resolve a lingering dispute with the Internal Revenue Service over the company’s tax returns from 1987 through 1991. So far, the IRS wants $8.3 million in back taxes.

AST on Friday named Scott Smith vice president of the company’s desktop division, which designs and markets the majority of the personal computers the company sells. It moved Larry Fortmuller in as vice president of the division that designs and manufactures advanced computers, called servers, for office networks. And it named Chris Imler director of marketing for its consumer products group. He will report to Smith.

The new titles were promotions for all three. Coming after three losing quarters and a layoff of 440 workers from the company’s Fountain Valley plant, the internal moves are a good sign, analysts said.

“You’ve seen people come and go pretty fast,” and that has worried investors and employees alike, said Miles Prescott, an analyst with the Renaissance Group investment firm in Pepperell, Mass. “It’s probably good news that they’re keeping some of their people inside the company.”

In its dispute with the IRS, the company has challenged the $8.3 million that the agency says is owed in back taxes for 1987 and 1988 so far. AST and the agency have been negotiating over the tax issue since at least 1993, an AST spokesman said.

The dispute centers on how AST allocated income between domestic and foreign units. The IRS also is investigating the company’s returns for 1989, 1990 and 1991, according to documents the company filed with the Securities and Exchange Commission.

An IRS spokesman said he could not comment on the ongoing investigation.