TAIPEI (Reuters) - Taiwanese micro-audio specialist Merry Electronics and China's Luxshare Precision Industry Co have agreed a potential 600 million yuan ($90 million) tie-up less than a month after a separate deal between the pair had been blocked.

Shenzhen-listed Luxshare Precision plans to invest 400 million yuan to 600 million yuan for a 40 percent to 60 percent stake in Merry's manufacturing unit in Suzhou, China, the companies announced on Monday.

The move follows swiftly on the heels of a rejection by Taiwan regulators of a plan by Luxshare Precision's Hong Kong unit to take a 25.4 percent stake in Merry for T$3.78 billion ($118 million).

Taiwan regulates China-related investments in the island's technology industry very carefully, given that the sector is a mainstay of the economy, with Taiwan's new government more wary of its neighbor than the previous government.

"We have not given up on the previous investment plan," Merry Electronics spokesman Allen Huang told reporters, adding that the new plan agreed in a letter of intent is aimed at giving both companies a better chance at clinching future business.

The new investment plan will expand capacity at the Suzhou plant, which mainly produces audio speakers, Huang said.

Luxshare Precision said the investment will increase the competitiveness of both companies in the audio electronics market. It made no mention of the previous plan to take a stake in the parent company.

Huang also said that the new deal is unlikely to require approval from Taiwan regulators because no capital in entering or leaving Taiwan via the investment into the Suzhou plant, but that the company will communicate with regulators on the deal.

Merry Electronics makes headsets, speakers, amplifiers and other small acoustic devices.

(Reporting by J.R. Wu; Editing by David Goodman)