United Technologies Corp is interested in making bigger investments in alternative energy, possibly including a majority stake in wind turbine maker Clipper Windpower Plc, a top executive at the diversified U.S. manufacturer said on Thursday.

We've been looking at alternative energy for a long time, United Tech Chief Financial Officer Greg Hayes said at an investor conference. We always liked the space. We see the movement toward clean energy as a space that we can participate in with the technologies that we have.

The Hartford, Connecticut-based company in December paid about $271 million for a 49.5 percent stake in Carpinteria, California-based Clipper. Hayes noted that technology developed by United Tech's aircraft engine business could be used to improve the performance of Clipper turbines -- an approach rival General Electric Co has also taken in the wind sector.

If over the next couple of years we see what we like, we always have the opportunity to take a majority share if we want, Hayes said of Clipper. If we like the market dynamics, I think you might see more in that space or other alternative technology spaces, which are adjacent to markets where we can use UTC technologies.

The world's largest maker of elevators and air conditioners also has a sizable fuel cell operation. Fuel cells use hydrogen to produce electricity without emitting carbon dioxide, a greenhouse gas associated with global climate change.

United Tech remains interested in other investments in the clean-tech area, Hayes said. The company has a $3 billion 2010 takeover budget, though more than half of that is going for its acquisition of GE's security business.

We hope to play these small bets into a bigger bet sometime down the road, Hayes said.

(Reporting by Scott Malone, editing by Gerald E. McCormick)