BARCELONA: ST-Ericsson is focusing strongly on Microsoft's platform to deliver chips and will be ready when Nokia ramps up production of new Windows Phones, the chief executive of the mobile chip venture said.

Nokia announced last Friday it would partner with Microsoft and would adopt Windows Phone software across its smartphones, replacing its home-grown platform.

So far Microsoft has allowed use of its software only on Qualcomm's chipsets, but ST-Ericsson Chief Executive Gilles Delfassy said that was due to change.

"We expect this situation will not prevail. Now everything has changed. The environment is different," he told Reuters in an interview, adding the company had already increased its focus on the Windows Phone platform.

"We will be ready when Nokia ramps big volumes," he said.

The joint venture between Sweden's Ericsson and STMicroelectronics of France is a key supplier to Nokia, Sony Ericsson and Samsung, and Delfassy said more major customers were to be announced later this year.

"A lot of new Tier 1 customers are using our platforms," he said.

There are only a handful Tier 1 phone makers in addition to its three major old clients. Semiconductor firms are usually not allowed to unveil their orders before clients publish products.

Loss-making ST-Ericsson has been cutting costs and revamping operations since it started operations in early 2009.

It aims to reach breakeven in the second half of 2012.

Delfassy said company key smartphone platform, the U8500, would ship in "small volumes in the first half, big volumes in the second half."

ST-Ericsson demonstrated at Mobile World Congress a reference design tablet which it has made with Quanta Computer Inc.

"We have several tablet programs that will turn to volumes this year," Delfassy said.