CMC Magnetics (TPE:2323) acquired 836,000 shares of FOCI Fiber Optic Communications for NT$310.8 million, according to a Tuesday Taiwan Exchange filing.

Shares gained about 4% in Wednesday's midday trade.

The shares were purchased between Nov. 25 and Dec. 2 at an average price of NT$371.8 each.

Following the acquisition, CMC Magnetics holds 322,000 FOCI shares, representing about 0.31% of the company. The purchase was made for portfolio management purposes, the optical storage products manufacturer said.