TORONTO (Bloomberg) — Canada's main opposition party called for a freeze on foreign buyouts to review the country's investment rules, adding pressure on the government to respond to a rash of foreign take-overs including a bid for Alcan.

The Liberal Party, which holds 100 seats in the 308-member House of Commons, is asking Prime Minister Stephen Harper's Conservative Party government to place a three-month moratorium on the acquisitions. It wants the government to set up an expert panel to study whether Canada's foreign-investment laws are too lax compared with other countries.

"We need to study the rules of our competitors and adapt accordingly," Liberal Leader Stephane Dion told reporters in Ottawa. Dion cited regulations in Pennsylvania that make it harder for New York-based Alcoa to be taken over. He added the freeze should only be on "major" transactions, without elaborating.

Alcoa's May 7 hostile take-over bid for Montreal-based Alcan triggered a backlash from opposition parties who say they're concerned foreign acquisitions of Canadian companies will lead to job losses. The government has said it will wait for recommendations from the industry ministry.

Alcoa's cash-and-stock offer for Montreal-based Alcan is valued at about $27.7 billion.

The Liberals also want parliamentary committees to hold hearings on the investment laws while the proposed three-month review takes place. The Liberals are calling on the government to take action before Parliament breaks for a recess.

The New Democratic Party, with 29 seats, last week issued a statement calling for immediate hearings on foreign take-overs, and the separatist Bloc Quebecois, with 49 seats, had also called for a review of Alcoa's offer.

The bid for Alcan brought to almost 600 the number of announced foreign take-overs in the past 16 months, valued at a combined $156 billion, according to Bloomberg data. That compares with $43 billion in 2005.