Today: Microsoft reportedly is willing to pay developers to create apps for Windows Phone 7. Motorola’s Droid X debuts tomorrow. Intel earnings boost tech stocks, but the economy pulls down the broader market.

Apple vs. Microsoft vs. Google

Microsoft — the Redmond, Wash., software megabehemoth — may be by far the dominant maker of computer operating systems. Its Windows mobile platform, however, is only the third-most-popular operating system in the market for smart new phones (at least according to a report this month from industry researcher comScore).

Today, Bloomberg News is reporting that Microsoft is paying developers to write apps for its coming Windows Phone 7 software as it competes to keep pace with Apple’s iOS and Google’s Android platforms.

“We are investing a lot to attract developers big and small to Windows Phone 7 to let them understand what the opportunity is and provide as many resources as we can to help them be successful on our platform,” Todd Brix, a senior director at Microsoft, told the news service. “We’re open for business and we want to work with them.”

According to comScore, Research In Motion’s BlackBerry is the No. 1 smartphone platform with 41.7 percent of U.S. subscribers in May. Apple’s iPhone is No. 2 at 24.4 percent. While Windows has a 13.1 percent share, it’s been losing ground to Google’s Android, which has 13 percent of the market.

Microsoft stock, by the way, closed today at $25.44, up 31 cents, or 1.2 percent. Google finished at $491.34, up $2.14 cents, or 0.4 percent. Apple closed at $252.73, up 93 cents, or 0.4 percent.

Google, meanwhile, gains another smart new phone in its Android army tomorrow with the debut of Motorola’s Droid X on Verizon Wireless’ network.

The Droid X includes features such as a 4.3-inch high-resolution display, HD camcorder and 8 megapixel camera. It costs $299.99 with a two-year Verizon contract, but the carrier is offering a $100 mail-in debit card rebate.

According to Bloomberg, MKM Partners, in a report by analyst Tero Kuittinen, raised its rating on Motorola stock to “neutral” from “sell” based in part on consumer interest in the Droid X. The stock also benefited from a report in The Wall Street Journal that Motorola was in talks to sell its telecommunications-equipment business to Nokia Siemens Networks.

Motorola stock closed at $7.46, up 25 cents, or 3.5 percent.

Intel stock climbs

Silicon Valley technology stocks rallied this morning after Intel — the Santa Clara chip bellwether — reported strong earnings after the stock markets closed Tuesday afternoon. However, investors’ concerns about the health of the economy pulled down the broader market later in the day.

Intel stock closed at $21.36, up 35 cents, or 1.7 percent. Earlier in the day, the shares climbed as high as $22.25.

A day earlier, Intel reported a $2.9 billion profit for its most recent quarter vs. a $398 million loss a year earlier, when the chip giant had to pay a large fine to the European Union. Revenue jumped 34 percent to a record $10.8 billion. With CEO Paul Otellini reporting healthy demand for personal computers, servers and “leading-edge technology,” Intel forecast $11.2 billion to $12 billion in revenue for its current quarter.

GM electric car

Hoping to spark consumer interest in its Chevrolet Volt electric car, General Motors is offering an eight-year or 100,000-mile warranty on the vehicle’s battery.

“The Chevrolet Volt’s batteries have exceeded our performance targets and are ready to hit the road,” Micky Bly, GM’s executive director of global electrical systems, said in a statement today.

“Our customers are making a commitment to technology that will help reduce our dependence on petroleum,” Bly said. “In turn, we are making a commitment to our customers.”

GM will start selling the Volt in California and other states late this year. According to The Associated Press, the Volt is expected to cost about $35,000.

Twitter ‘@earlybird’ deals

Twitter — the San Francisco microblogging site (which lets you share your thoughts online, as long as you can keep them to 140 characters or less) — revealed today that it’s working with deal sites Groupon and Gilt Groupe on offers for its new ‘@earlybird’ feed.

In a post on the startup’s official blog this morning, spokesman Matt Graves said ‘earlybird’ offers will come from those sites and directly from Twitter advertisers. Since the feed was announced last week, more than 46,000 Twitter members have signed up to follow ‘earlybird.’

Silicon Valley tech stocks

Up: Apple, Google, Cisco Systems, Oracle, Intel, Hewlett-Packard, VMware, eBay.

Down: Gilead Sciences, Yahoo.

The tech-heavy Nasdaq composite index: Up 7.81, or 0.3 percent, to 2,249.84.

The blue chip Dow Jones industrial average: Up 3.70 to 10,366.72.

And the widely watched Standard & Poor’s 500 index: Down 0.17 to 1,095.17.

Check in weekday afternoons for the 60-Second Business Break, a summary of news from Mercury News staff writers, The Associated Press, Bloomberg News and other wire services. Contact Frank Russell at 408-920-5876. Follow him at Twitter.com/mercspike.