Aegon, which has been winding down and selling operations after requiring state aid at the height of the credit crisis in 2008, said on Tuesday the disposal would help it repay outstanding aid of 1.125 billion euros ($1.6 billion).
The deal is the latest in a round of consolidation in the North American life reinsurance market, as companies try to position themselves for a rebound after the financial crisis.
Last October, Warren Buffett's Berkshire Hathaway agreed to buy Canadian insurer Sun Life Financial's reinsurance business.
Europe is SCOR's biggest market and Transamerica will boost its market share in the United States, where it currently earns less than 30 percent of its global life reinsurance premiums.
'With the acquisition of a major mortality risk reinsurance portfolio in the United States, SCOR aims to further increase its geographical diversification,' it said.
SCOR, which also sells property and casualty reinsurance, eclipsed Reinsurance Group of America as the lead bidder for Transamerica in March, according to sources familiar with the matter.
'The good news for SCOR is that the price is pretty good, and there is no capital increase,' said Francois Boissin, analyst at Exane BNP.
SCOR said it would pay for the deal through its own funds and a potential debt issue of around 200 million euros, without the issuance of any new shares.