Company: Johnson Controls Inc

NEW YORK (Reuters) - America's skyscrapers, many built before World War Two, are showing their age. IBM's "building whisperer," Dave Bartlett, believes many of these buildings could use a diet.

NEW YORK (Reuters) - The Empire State Building has long been a signature feature of Manhattan's skyline. But owners of the iconic edifice, planning a $1 billion initial public offering, hope to convince investors and tenants that it's what's on the inside that really counts.

From the entire S&P 500, which stocks are analysts expecting to have the biggest pops?

Stocks finished modestly higher Thursday, posting a three-day rally, thanks to a better-than-expected jobless claims report and as financials rallied following BofA's earnings report. Still, gains were largely muted throughout the session as investors hesitated to jump in following the recent run-up in stocks.

Bringing greater energy efficiency to commercial buildings promises to be big business. The market is estimated to increase to $100 billion by 2017. Companies doing retrofits stand to reap the benefits from buildings going green.