By Matt Egan, CNN Business

(CNN) -- General Electric might be under new management, but its quest to get smaller continues.

In the first deal under new CEO Larry Culp, GE (GE) said on Monday it's unloading a $1 billion portfolio of energy investments to private-equity firm Apollo Global Management.

The portfolio holds about 20 investments in renewable energy, natural gas and midstream infrastructure assets. The investments -- most of them equity stakes -- were housed in GE Capital's Energy Financial Services unit, which invests and lends to GE's power and renewable energy customers.

GE and Apollo (APO) said the portfolio is worth about $1 billion, including debt. Details of the transaction, which is expected to close before the end of the year, were not disclosed.

The energy sale comes just a week after embattled GE unexpectedly ousted CEO John Flannery after barely a year on the job. Culp, the new boss, is the first outsider CEO in GE's 126-year history.

Debt-riddled GE has been racing to raise cash by saying goodbye to countless businesses, including some it's held for more than a century.

In recent months, GE has agreed to sell its 111-year-old locomotive division and it's struggled to find a buyer for the light bulb unit that Thomas Edison founded. GE also announced plans to get rid of the health care division, which makes MRI machines, and to exit its stake in Baker Hughes (BHGE), the oil and gas services firm.

At the same time, GE continues to shrink GE Capital, the financial business that nearly ruined the company during the 2008 financial crisis. GE Capital has been bleeding billions because of insurance losses and an investigation into WMC, a subprime mortgage lender that GE shut down a decade ago.

In August, GE agreed to sell its energy debt financing business to Starwood Property Trust (STWD) for $2.6 billion.

GE Capital said it continues to provide capital to GE's power and renewable energy customers, despite the sale announced on Monday. GE Power, the largest remaining business at GE, is reeling from a shift away from fossil fuels and a glitch with its gas turbines.

Wall Street is betting Culp, the former CEO of industrial manufacturer Danaher, will act quickly to stop the bleeding at GE. After plunging to nine-year lows in September, GE shares spiked 17% during Culp's first week. It was GE's best week since 2009.

GE shares bounced another 2% on Monday following the latest deal and an optimistic research report from Barclays. The firm upgraded GE shares to "overweight" from neutral and predicted Culp will be more aggressive in cutting costs at GE Power.

"We think the upside potential in the shares is considerable now that an outside CEO has been put in place," Barclays analyst Julian Mitchell wrote to clients.