The last time Microsoft revamped its Office for Mac was in October 2010. Image source: Microsoft.

It's been nearly four years since Microsoft (NASDAQ:MSFT) has updated its Office for Mac productivity suite. But As Apple's (NASDAQ:AAPL) Mac sales continue to gain market share among PCs, Microsoft's Thorsten Hubschen, who oversees Office in Germany, has revealed that an internal reorganization at Microsoft has resulted in renewed efforts on its Office for Mac suite.

The robust Office for Mac business
Apple's Mac business didn't just slightly outperform the PC market in the fourth quarter of 2013 -- it crushed it. During the quarter, Apple's Mac shipments grew 19% from the year-ago quarter, putting Apple's Mac growth about 25 percentage points ahead of the PC market's decline during the same period. While it's been five quarters since Apple posted year-over-year quarterly unit sales growth for its Mac segment, it does consistently outperform the PC market -- in every quarter except one since 2005 to be exact.

iMac. Source: Apple.

The result is that Apple's share of the worldwide PC market is growing to 5.5% today, from 2.1% in 2005.

With Apple's Mac business gaining share, it makes more sense than ever for Microsoft to focus on an Office product for Mac.

Great news for investors
Considering that Office is one of the Microsoft's largest contributors to the company's operating income, investors should be enthusiastic about Microsoft's renewed interest in developing Office for other platforms. A renewed push for cross-platform versions of Office means the company can focus less on defending its Windows market share and more on providing excellent products and services.

While Hubschen didn't comment on Microsoft's plans for a version of Office for Apple's iOS, Microsoft insider Mary Jo Foley said last month that an iPad version of Office is still in the works.

Microsoft continues to trade fairly conservatively at just 14 times earnings. Still a cash cow, simply maintaining revenue and current pricing power would make the stock an excellent investment. With the market giving the stock so little respect, even small moves like a renewed interest in Office for Mac should give investors incremental confidence in the business.