CALGARY, Alberta (Reuters) - Canada's oil sands producers aren't feeling the love.

There's no question that Alberta's huge unconventional crude deposits hold some of the richest potential for supplying North America and even Asia with oil.

Investors don't seem to care right now.

Maybe it's fear that a rebound in development is fleeting after the 18-month downturn that prompted the halt of C$90 billion ($87 billion) of projects. It may be concern about what policy-makers might do in the name of cutting carbon emissions or tightening other environmental regulations.

Either way, stocks of oil sands companies still lag 2008 levels, and in some cases are up only a tad from 12 months ago, when economies had just begun to recover. "There's a disconnect. Global companies are seeing the value in the oil sands. They're acting on it, and investors are not reflecting that same value in the stocks," Versant Partners analyst Mark Friesen said. "Investors are telling the market that they're not willing to pay for resources."

Case in point: BP Plc's recent deals aimed at kick-starting its oil sands operations. In the past two weeks, the British oil major took on Devon Energy Corp as a partner in its Kirby oil sands project, then snapped up a majority stake in a property owned by Value Creation Inc.

Now look at shares of Suncor Energy Inc, the biggest oil sands producer which bulked up last year with a C$22.8 billion takeover of Petro-Canada. Closing at C$30.80 on the Toronto Stock Exchange on Friday, Suncor is down 38 percent from March 2008, a year before it even announced the deal.