* Offer at 53 percent premium to FSI's Aug 10 close
* Deal unanimously approved by boards of both firms
Aug 13 (Reuters) - Japan's Tokyo Electron Limited said it will acquire chip-equipment maker FSI International Inc for $252.5 million in cash, to add a key technology to its chipmaking capabilities.
The deal, valued at $6.20 per share, represents a 53 percent premium to FSI's closing price of $4.04 on August 10. Trading in the shares was halted on Monday.
FSI, which provides cleaning and surface preparation equipment, will complement Tokyo Electron's offerings, the Japanese company said in a statement.
"Surface preparation has increasingly become a critical technology in semiconductor manufacturing, and Tokyo Electron Limited is focused on improving its market position," the company said.
Tokyo Electron said the deal which has been unanimously approved by the boards of both companies will be financed with existing cash resources.