NEW YORK (TheStreet) -- Diamond Resorts Int'l  (DRII) stock is gaining 24.19% to $29.89 on heavy trading volume on Wednesday morning after the vacation resort operator agreed to be acquired by Apollo Global Management (APO) in a transaction valued at $2.2 billion.

Shares of Apollo are rising 0.27% to $15.08 this morning.

The New York City-based private-equity firm agreed to pay $30.25 per share to acquire Diamond Resorts, representing a 26% premium to the closing share price on Tuesday.

The transaction, which will be completed though an all-cash tender offer, is expected to close in the next few months.

"This transaction is an excellent outcome for our shareholders," Diamond Resorts CEO David Palmer said in a statement. "We are confident that Diamond Resorts will continue to be a vibrant company for our employees, partners and customers, and I am excited about the future of Diamond Resorts."

So far today, 21.07 million shares of Diamond Resorts have been traded, compared with its average daily volume of 1.06 million shares.

Separately, Diamond Resorts has a "hold" rating and a letter grade of C at TheStreet Ratings because of the company's revenue growth, impressive record of earnings per share growth and compelling growth in net income, which offsets generally higher debt management risk, weak operating cash flow and generally disappointing stock performance.

You can view the full analysis from the report here: DRII

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.