Dane Glasgow, general manager of Windows Live Search, is leaving Microsoft - the second executive to quit the company's Internet search group in a month.

Last month, Microsoft acknowledged the departure of its highest-ranking search executive, Christopher Payne, corporate vice president of Windows Live Search.

Microsoft has invested heavily in recent years to develop its own Internet search engine and accompanying search advertising platform, in an effort to compete with Google and Yahoo and benefit from the fast growth in online advertising.

However, the results have been disappointing. Microsoft lags in a distant third place in web search usage and it has not been able to capitalise as much as expected from the boom in search engine advertising.

In a bid to use its strong presence in the enterprise to lift its web search presence, Microsoft last month acknowledged it is offering financial incentives to large enterprise customers whose employees use Microsoft's Live Search engine.

In exchange for their employees' Live Search usage, Microsoft is providing "service or training credits" to these enterprise customers, the company said.