Taiwan's United Microelectronics Corp, the world's second biggest contract microchip maker, plans to triple its stake in Chinese chip producer Hejian Technology to 45 percent, officials said Thursday.

UMC plans to spend $87 million on the deal, which will give it 30 percent of the shares in Hejian on top its existing 15 percent holding, the Taiwanese company said in a statement.

The deal is still waiting for approval from the Taiwanese government, which last year cancelled a planned merger between the two companies, saying the way they intended to finance the transaction was not in accordance with the rules.

UMC bought 15 percent of Hejian in a 2005 deal valued at Tw$3.5 billion ($110 million), which analysts believe was mostly paid in kind via a continuous transfer of valuable technologies.