For TSMC, sales of 16.81 billion Taiwan dollars (483 million US dollars) were up 10.1 percent from April of this year, a company spokesman said.

"The month-on-month rise in sales reflected shipment growth and a wider product portfolio," he said.

In the first five months of this year, TSMC's sales rose 10.9 percent to 71.4 billion dollars.

At an April 29 investor conference, TSMC chairman Morris Chang said he expected wafer shipments to rise 20 pct quarter-on-quarter in the three months to June and the average selling price to increase four percent.

The company also expected its overall capacity utilisation rate to rise to 80 pct in the second quarter from 67 pct in the first, Chang said.

For UMC, sales in May totalled 7.36 billion dollars, up only marginally on April's 7.32 billion dollars.

In the five months to May, UMC's sales rose to 32.58 billion dollars from 24.03 billion a year earlier.

In an analyst conference of last month, UMC said its capacity utilisation rate was expected to rise to 80 percent in the second quarter of this year, up from 67 percent from the first quarter.

Separately, TSMC said it has recently signed investment contracts with Shanghai authorities to kickstart its 898 million US dollar chip plant investment in China.

The project involves the construction of an eight-inch (200 millimetre) wafer plant in Shanghai's Songjiang Science Park with a monthly capacity of 35,000 wafers using 0.25 micron technology.

SPACE.WIRE