Busy months at the rumor mill

Smiths CEO Philip Bowman

And then there's all the conjecture. Is Smiths Group looking to ditch its medical business? Is Roche ($RHHBY) trying to get out of the glucose-monitor game? Does anyone have $1 billion and an affinity for ICU Medical ($ICUI)? The year has hardly been short on buyout rumors, whether unnamed sources are warning of high-dollar deals down the line or struggling companies are looking for a check to keep the doors open.

Among the said-to-be sellers is Smiths, whose medical device operation could well be worth $5 billion. CareFusion ($CFN) is said to be taking a look at buying the maker of imaging devices and hospital-based technology, but, in the past, Smiths hasn't seemed keen on selling. Smiths Medical pulled in about $1.3 billion in revenue last year, good for 28% of the conglomerate's $4.6 billion, and the company rejected a $3.7 billion offer from private equity firm Apax Partners back in 2011.

Roche, however, may be a more likely bet. In May, Reuters reported that the drug and diagnostics giant was exploring a sale of its blood glucose meter business, citing concerns about pricing pressures abroad and reimbursement cuts in the U.S. Roche Diagnostics has snatched up an ever-increasing share of the global market and rakes in billions a year, but the division's diabetes business has stayed stubbornly flat, and Roche is in the midst of a restructuring that will cut 100 jobs from the unit. With little hope for a dramatic turnaround, Roche may be looking to unload its meter arm to a company like Johnson & Johnson ($JNJ) or Medtronic ($MDT), both big enough devicemakers to be able to squeeze some cost efficiencies out of a deal.

Theragenics CEO Christine Jacobs

But not everyone has the luxury of a clandestine bidding process. Theragenics ($TGX) has watched its revenue careen into the red over the past year, and now the company has received an offer of up to $71.4 million from private equity outfit Juniper. The company hasn't made a final decision on whether to sell itself, but, considering its stock price jumped about 36% after the offer announcements, shareholders seem to think it's a fine idea.

Thoratec ($THOR), maker of heart devices, has been in a similar situation for a while. Major shareholder Oracle Investment Management has repeatedly asked the company to find itself a buyer, saying its strengths in the left ventricular assist device market would be an ideal fit for Medtronic or St. Jude Medical ($STJ).

And those are just the would-be deals that have bubbled to the surface. Unnamed sources can make for entertaining weeks of rumoring--and, as we learned in the protracted Life Technologies process, they provide plenty of fodder for punning headline writers--but most M&A goes unheralded until there's ink on a line. And, with 6 months left in what has already been an acquisition-friendly year, we'll just have to wait and see who reaches deepest and shells out for 2013's biggest buyout.

Busy months at the rumor mill