MetLife is building up cash as the United States creeps closer to default, and may use that extra money for investments, the largest U.S. life insurer said on Friday.

We've added several billion dollars of excess cash, which we think is a prudent thing to do in an environment of uncertainty, Chief Investment Officer Steve Goulart said on a conference call with analysts a day after the company reported its quarterly financial results.

The cash lets the company put a little bit of an opportunistic hat on as well and, to the extent that there are investment opportunities that become available, we want to be positioned to take advantage of them, Goulart said.

MetLife shares rose 1.5 percent to $40.40 in morning trading, making it one of the top-10 gainers in the S&P 500 on an otherwise down day. On Thursday, the company reported a smaller profit for the second quarter on higher claims expenses, but still beat expectations.

(Reporting by Ben Berkowitz. Editing by Robert MacMillan)