Sierra Health Services Inc. said on Wednesday that its shareholders voted overwhelmingly to approve its acquisition by UnitedHealth Group Inc. for $43.50 per share.
Both companies expect the deal to close by the end of the year, if not sooner, Sierra said.
Sierra said more than 99 percent of the votes cast approved the merger.
UnitedHealth, the largest U.S. health insurer by market value, said in March that it would buy Sierra for more than $2.4 billion to expand in the fast-growing Las Vegas area.
Sierra provides health benefits through employers to about 310,000 members in Nevada, virtually all in the Las Vegas area, where Sierra is based.
It also offers Medicare plans to about 260,000 members, including 60,000 in a full-service Medicare Advantage plan in Nevada and 200,000 in Medicare plans offering prescription drug coverage in about 30 states.
Sierra also has 60,000 members in Nevada enrolled in a Medicaid plan for low-income residents.
Sierra Health shares closed down 3 cents at $41.47 on the New York Stock Exchange, while UnitedHealth shares closed off 4 cents at $51.75, also on the NYSE.