Exhibit 99.1
Explanation of Responses
(1) Pursuant to a Note Purchase Agreement, dated as of June 25, 2004, by and
among Micro Therapeutics, Inc. (the "Company"), Warburg, Xxxxxx Equity
Partners, L.P., a Delaware limited partnership (together with three
affiliated entities, "WPEP"), and the other investors named therein (the
"Note Purchase Agreement"), WPEP agreed to purchase an aggregate principal
amount of $10,000,000 of exchangeable promissory notes from the Company
(the "Exchangeable Notes"). The Exchangeable Notes accrued interest at 7%
per annum, which interest compounded quarterly. On August 18, 2004, WPEP
exchanged all of the Exchangeable Notes held by WPEP for 3,259,866 shares
of common stock, of which Warburg, Xxxxxx Equity Partners, L.P. received
3,080,574 shares and three entities affiliates with Warburg, Xxxxxx Equity
Partners, L.P. received an aggregate of 179,292 shares. The number of
shares of common stock received by WPEP was determined by dividing (i) the
aggregate principal balance on such Exchangeable Notes plus accrued and
unpaid interest thereon at August 18, 2004 by (ii) $3.10.
(2) The sole general partner of WPEP is Warburg Pincus & Co., a New York
general partnership ("WP"). Warburg Pincus LLC, a New York limited
liability company ("WP LLC"), manages WPEP. By reason of the provisions of
Rule 16a-1 of the Securities Exchange Act of 1934, as amended, WPEP, WP and
WP LLC may be deemed to be the beneficial owner of an indeterminate portion
of the 24,336,759 shares of the Company's common stock owned by Micro
Investment, LLC, a Delaware limited liability company, which is indirectly
controlled by WPEP.
