The Redmond, Wash., software company expressed an interest in the Waterloo, Ontario, pioneer in wireless handheld devices and services more than a year ago, but it didn't result in a deal.
A Microsoft-BlackBerry combination could make Microsoft a more substantial player in the smartphone race, the Journal said.
But it would also likely create difficulties with Microsoft's current partnership with Nokia Corp., another former cellphone leader, the newspaper said.
Nokia makes smartphones based on Microsoft's Windows operating system.
Microsoft declined to comment.
The Journal report came a day after BlackBerry said it decided to "explore strategic alternatives" after a line of wireless devices operating on a new operating system, dubbed BlackBerry 10, got a tepid response in the consumer market at its launch this spring.
BlackBerry was betting the devices would help it catch up with Apple Inc.'s iPhone and phones running on Google Inc.'s Android software.
The company said Monday its board set up a special five-person committee and hired JPMorgan Chase & Co. to examine its options, including a sale, joint ventures and strategic partnerships.
It also hired Hill+Knowlton Strategies Inc., which Canadian newspaper The Globe and Mail said has experience seeking government approvals for major international takeovers.
The reported interest in Microsoft comes as BlackBerry said Prem Watsa, chief executive officer of its biggest shareholder, Fairfax Financial Holdings Ltd., resigned from the BlackBerry board Monday "due to potential conflicts that may arise" from the strategic review.
The Globe and Mail said Fairfax executives were exploring ways of putting together a group to acquire BlackBerry.
Fairfax, which owns 10 percent of BlackBerry, is talking with private-equity and industry players that might be interested in participating in a buyout, people familiar with the situation told the newspaper.
Watsa has said Fairfax intends to retain its stake in BlackBerry and feels the market is undervaluing the company, the newspaper said.
BlackBerry declined to comment. Watsa had no immediate comment.
BlackBerry was a pioneer in the smartphone industry with the introduction of phones capable of sending and receiving messages wirelessly.
It once controlled more than half of the U.S. market for phones that could handle email and Web-browsing as well as phone calls.
BlackBerry now has a global market share of just 2.9 percent, U.S. technology research company International Data Corp. said last week, down from 4.9 percent in the same second-quarter period last year.
"However, BlackBerry has shown steady progress since the launch of its BB 10 platform, which has grown to three models, additional mobile operators, and a greater presence within its total volumes," IDC said. "It is still early days for the platform, however, and BlackBerry will need time and resources to evangelize more end users."
The BB 10 operating system includes two smartphones and a tablet handheld device.
BlackBerry has a market capitalization of about $5.8 billion. It had nearly $3 billion in cash and short-term investments as of June 1. It also had no debt, which The New York Times said meant it could likely support the financing a leveraged buyout would require.