MannKind Corp. said Tuesday afternoon that it has agreed to sell 27 million shares of its common stock to the company’s chief executive and founder, Alfred Mann, as well as two groups of investors.

Of the total shares offered, 16 million were sold to Mann for $9.41 per share, and an additional 11 million were sold to the other investors for $9.03 apiece. The Valencia-based biotech said it expects to gross $250 million from the sale, which is expected to close by Oct. 5.

Mann, who founded the company in 1991, now owns about 44.5 percent of the Valencia-based biotech firm, according to regulatory filings.

In addition to the sale, Mann is extending a $350 million credit facility to the company until the end of 2009, which replaces a $150 million credit facility from him.

The company said it plans to use the cash to fund development of Technosphere, an inhaled insulin product, may be submitted for U.S. Food and Drug Administration approval by the end of 2008.

Shares in MannKind closed up 7.3 percent to $10.10 in trading Tuesday on the Nasdaq.