It’s not as though anyone really considered Nokia (NOK) an arms’ length partner for Microsoft’s (MSFT) Windows Phone prior to last week’s $7.2 billion buyout. But whatever secrets the two companies kept from one another aren’t going to stay hidden, according to a top Windows Phone exec.

Joe Belfiore, the Microsoft corporate vice president in charge of Windows Phone, in a CNET interview, said that while the companies previously talked up their close partnership, it wasn't always that way in practice.

"There are real-world examples of situations where Nokia was building a phone and keeping information about it secret from us," said Belfiore. "We would make changes in the software, or prioritize things in the software, unaware of the work that they're doing,” he said.

That’s not an unusual circumstance for Microsoft and its other hardware partners, but with Nokia safely tucked under Microsoft's arm we should expect fully open books between the two, which should result in improved phones hitting the market more quickly, according to Belfiore.

Belfiore also reiterated claims made by outgoing Microsoft chief executive Steve Ballmer and, separately, Microsoft Operating System executive vice president Terry Myerson, that the Nokia acquisition won’t threaten the company’s Windows Phone OEM relationships. In the wake of the Nokia purchase, Microsoft has made it clear that it still intends to license Windows Phone and has gone out of its way to address the question of just who will want it.

Inasmuch as Nokia was Microsoft’s lead sled dog for Windows Phone, you’d think that after Microsoft takes over the Finnish company’s operations, there won’t be much of a clamor among other OEMs for the mobile OS. And, even more to the point, it’s unlikely OEMs currently making Windows Phone-based devices will treasure the thought of competing head-to-head with Microsoft for handset sales. It’s difficult to believe HTC and Samsung are happy about their Windows Phone investments right about now.

But Belfiore told CNET that Microsoft’s Windows Phone OEM business won’t destabilize with Nokia in tow.

"Some of our partners have come, and some of them have gone over the years," he said. "It's not likely to change the big picture."