The Toronto-based company said it plans to sell 22.5 million units at C$10 a unit and raise C$225 million ($184 million). It had initially set out to raise C$125 million by selling 12.5 million units at C$10 apiece.

Alignvest, headed by serial entrepreneur and private equity industry veteran Reza Satchu, is backed by Canadian business figures that include Nadir Mohamed, former head of Rogers Communications (>> Rogers Communications Inc.); Donald Walker, chief executive of autoparts maker Magna International, and Bonnie Brooks, vice chair of retailer Hudson's Bay (>> Hudson's Bay Co).

The company does not plan to limit its acquisition hunt to any particular sector. It does, however, intend to focus its search on businesses that operate in North America and specifically ones with ties to Canada. It is looking to acquire companies with an enterprise value between C$250 million and C$1.25 billion.

An industry source involved in the IPO said about 60 percent of the offering was allotted to Canadian investors, including some large asset managers, and the rest went to U.S. investors.

The source said the offering was up-sized after demand from investors far exceeded initial expectations. Alignvest, he added, could have raised between C$450 million and C$500 million given the demand.

Including an over-allotment option granted to the banks that are underwriting the deal - TD Securities, Cantor Fitzgerald, BMO Nesbitt Burns and CIBC World Markets - proceeds from the IPO could climb to C$258.75 million, making it the largest offering from a special purpose acquisition vehicle in Canada this year.

INFOR Acquisition (>> INFOR Acquisition Corp) raised C$200 million excluding any over-allotment proceeds in May, while Dundee Acquisition Ltd (>> Dundee Acquisition Ltd) raised some C$100 million on the same basis in April.

Stikeman Elliott LLP is acting as Canadian legal counsel to Alignvest, and Osler, Hoskin & Harcourt LLP is acting as Canadian legal counsel to the underwriters. Ellenoff Grossman & Schole is acting as legal counsel to Alignvest and the underwriters in the United States.

(Reporting by Euan Rocha and John Tilak)

By John Tilak and Euan Rocha