Japan's Asahi will buy Zoll Medical Corp (ZOLL.O) for $2.21 billion,

TOKYO (Reuters) - Japan's Asahi Kasei Corp (3407.T) will buy Zoll Medical Corp (ZOLL.O) for $2.21 billion, or $93 a share, a premium of 24 percent over the medical equipment maker's last closing share price, the two companies said on Monday.

Both boards have approved of the cash deal, and the transaction should close in the second quarter of this year, they said in a joint statement.

"This transaction will allow us to build on Zoll's strong U.S. business position and its technology leadership, with Zoll forming the cornerstone of our critical care business," Asahi Kasei President Taketsugu Fujiwara said.

Zoll, a maker of resuscitation and critical care devices, derives a fifth of company revenues from a wearable defibrillator, it said in November. The company will become a wholly owned subsidiary of Asahi Kasei on completion of the deal and the current Zoll management, units and operations will remain intact.

Zoll said on January 19 it returned earnings per share of $0.29 for the first quarter, above expectations for $0.26 on revenues of more than $133 million.

Zoll's shares rose last month to a record high of $76.22, up more than 64 percent from a year earlier and up from just over $11 in 2009.

Asahi Kasei identified ageing as a trend and sees emerging demand for healthcare as a strategic sector for the company in the future. Asahi Kasei signed an agreement last July with Zoll to market and distribute its wearable defibrillator in Japan.

Shares in Asahi Kasei closed on Monday at 518 yen, up from 517 on Friday. They have risen 11.6 percent this year, underperforming the benchmark Nikkei (.N225), which is up almost 17 percent so far this year.

The Japanese company derives more than half of its sales from its chemicals and fibres business with another third coming from homes and construction materials. Electronics make up 9 percent of sales and health care 7 percent.

Almost 90 percent of its operating profit comes from chemicals and fibres and its homes and construction segments. Just over 5 percent comes from health care.

(Reporting by Miki Kayaoka and Neil Fullick; Editing by Chris Gallagher)