In one of those classic maturing startup situations, Big Fish Games founder Paul Thelen has moved into a new role as chief strategy officer focusing on product strategy. He tapped a business expert to serve as chief executive as the 5-year-old company enters its next phase of growth.

Jeremy Lewis, a 14-year veteran of Goldman Sachs, is now president and chief executive, the Seattle casual games company announced today. Lewis, 38, joined Big Fish in 2006 as president and chief operating officer.

I wondered if the move also signaled that the company is positioning itself for a merger or even to go public. But it doesn't sound like there's anything imminent.

The message I received from Lewis is that the company is keeping its options open, but the transition was a natural evolution. From a chat we had today:

"We will continue to make decisions and judgments that lend themselves to having more options in terms of what we would do both internally and externally with the business," he said. "Whether it's a business that we choose to go in, a partnership we wish to create with an outside company, entry into a market overseas, all of our decisions we try to handicap them so they enhance the degree to which we have strategic flexiblity rather than limit it."

Lewis said his favorite game is Big Fish's Azada -- a strategy game, obviously.