UnitedHealth Group Inc. said Wednesday it will raise its quarterly dividend 30 percent to 16.25 cents, as it continues to reap the benefit of strong quarterly financial performances that have left it and other health insurers with money to give back to shareholders.

The Minnetonka, Minn., insurer said the dividend increase and a new share buyback program it also announced Wednesday reflect continued growth in both its benefits and services businesses.

Competitors WellPoint Inc., Aetna Inc. and Humana Inc. also have launched quarterly dividend payments this year, using growing supplies of cash they have left over after stocking reserves for claims. The five largest health insurers, a group that also includes Cigna Corp., all reported better-than-expected first-quarter earnings, with net income growth ranging from 4 percent to Cigna's 52 percent.

Insurers have been helped in part by health care use that has grown at a slower-than-expected rate as the economy recovers from a deep recession.

Last May, UnitedHealth became the first big insurer to announce a new quarterly dividend, when it launched a 12.5-cent payment. The increased amount will be paid June 21 to shareholders of record at the close of business June 7.

Cigna is the only health insurer out of those five that has not increased its dividend. It still offers an annual payment of 4 cents.

UnitedHealth said Wednesday its board also authorized the repurchase of up to 110 million shares over time. That replaces a previous buyback authorization from February 2010 for 120 million shares. About 28 million shares were left under that plan.