Research in Motion (Nasdaq: RIMM) investor Victor Alboini said he'd welcome a bid for the ailing BlackBerry developer by International Business Machines Corp. (NYSE: IBM) for its enterprise services unit, as he's advocated for months. As well, he said Microsoft (Nasdaq: MSFT) might also be a welcome bidder.

"I'm not at all surprised that IBM would be looking," Alboini said Friday. "This kind of business - service and software for enterprises - is what they've been focused on."

Bloomberg News reported the informal approach earlier on Friday.

Alboini, whose company started acquiring shares in RIM a year ago, prompting others, such as New York investor Leon Cooperman's Omega Advisers and Canadian investor Prem Watsa to join him, said the underlying value of RIM's BlackBerry network is its nearly 80 million customers who pay monthly fees for their smartphones and e-mail services.

He estimated the value of that might be as much as $9.6 billion, more than double RIM's market capitalization of $4.1 billion at Thursday's close.

Meanwhile, analyst Peter Misek of Jefferies said he valued the enterprise business much lower, around $2 billion, and said a takeover of the BlackBerry services unit might require layioffs of 80 percent of the employee force, far beyond what CEO Thorsten Heins has done.

Moreover, Misek said, the software codes are "too tightly linked" between the enterprise business and manufacturing to make a split possible.

Still, Alboini said he was concerned that Watsa, whose Farifax Financial holds a RIM stake around 10 percent, and former RIM CO-CEO MIke Lazaridis, with another 10 percent, might impede any approach that would split the company.

New RIM CEO hired Royal Bank of Canada (NYSE: RY) and JPMorgan Chase (NYSE: JPM) to provide strategic advice to the company but has remained committed to keeping the company whole in remarks to investors at the company's July 10 annual meeting.

Alboini has also said the other parts of RIM, its manufacturing and product development side, could attract a buyer such as Microsoft or Samsung Electronics (Seoul: 005930), which have previously been suggested as bidders.

Microsoft, for example, plans to enter the tablet market next quarter with its Surface Tablet as well as release Windows 8 Mobile for smartphones. To date, the only top smartphone maker to have adopted the Windows OS for phones is Finland's Nokia Oyj (NYSE: NOK).

RIM's share of the smartphone market dwindled to below 5 percent in the second quarter from 12 percent a year ago, market researcher IDC reported, as smartphones running either on the iOS from Apple (Nasdaq: AAPL) or Android OS from Google Inc. (Nasdaq: GOOG) have taken about 85 percent of the market.

As a result, RIM has reported lower revenue as well as losses. In the first quarter ended June 2, its net loss was $518 million, or 99 cents a share, reversing prior-year net income of $695 million, or $1.33 a year earlier. Revenue fell 43 percent to $2.8 billion.

Neither RIM nor IBM would comment on the report.

RIM shares rose as much as 9 percent in early Friday trading before easing back to $8.29, up 49 cents, or 6 percent, at the close. They're down 62 percent for the past 52 weeks.