Google's 7-inch tablet PC, which the company co-developed with Asustek computer, is set to start shipping in June with initial shipments to reach about 600,000 units. The machine will be officially released in the market in July, according to sources from the upstream supply chain. However, Asustek has declined to comment.

Google originally planned to release its entry-level 7-inch tablet PC in May, but design and costs did not reach its expectations, and the product was delayed to July for some minor adjustments.

The 7-inch tablet PC is expected to achieve total shipments of 2-2.5 million units in 2012.

With Samsung Electronics, Asustek Computer and Acer are releasing new 7-inch tablet PCs, competition in the 7-inch tablet PC market is expected to turn fierce in the second half of 2012.