Stikeman Elliott, one of the largest firms in Canada, has grabbed lead roles on two major M&A deals announced Monday.

The firm is advising Russia’s state-owned AtomRedMetZoloto (ARMZ)—the successor to the Soviet Union’s nuclear industry—in connection with its $1.3 billion acquisition of Canada’s Uranium One, while representing Toronto-based Harry Winston Diamond Corporation on the $1 billion sale of its watch and jewelry unit to The Swatch Group of Switzerland.

Stikeman corporate partner Sean Vanderpol and antitrust partner Shawn Neylan are heading the firm’s team advising Harry Winston on the Swatch deal, which includes $750 million in cash and $250 million in debt, along with associates Adeline Lee and Michael Kilby.

Lyle Hepburn, corporate secretary for Harry Winston and counsel with Toronto’s Markes Lawyers, did not respond to a request for comment about the transaction. Hepburn retired from Harry Winston’s board of directors in November 2012.

After Hepburn’s former firm, Beach Hepburn, broke up in 2010, top mining partner Mark Wheeler joined Toronto-based Borden Ladner Gervais. Wheeler got the call from Hepburn and Harry Winston last November when the company spent $500 million to acquire diamond assets owned by Australian mining giant BHP Billiton, including the massive Ekati Diamond Mine in Canada’s Northwest Territories. (BHP was represented on the deal by Canadian firm Davies Ward Phillips & Vineberg, which also helped the company unload its 33.3 percent stake in an aluminum oxide mine in Guinea late last year to a joint venture partner amid a deteriorating regulatory environment in the West African country.)

Harry Winston’s latest deal sees the company sell its timepiece and diamond jewelry division to Biel-based Swatch as Reuters reports the world’s largest watchmaker looks to gain on its rivals in the consolidating luxury goods industry.

Hanspeter Rentsch, chief legal officer for Swatch and a member of the company’s executive management board, led an in-house team working on the deal. Swatch is not using outside counsel for the transaction.

Swatch wasn’t the only company eyeing expansion via a transaction involving Stikeman as the new week got under way.

The firm, which promoted seven lawyers to partner this month, is representing Russia’s state-owned uranium mining company ARMZ on its proposed purchase of the 49 percent of Vancouver-based Uranium One it doesn’t already own.

Leading the Stikeman team advising Moscow-based ARMZ are M&A partner Amanda Linett, tax partner John Lorito, international investment partner Susan Hutton, pensions and benefits partner Andrea Boctor, labor and employment head Lorna Cuthbert, and associates Alethea Au, Evan Marcus, Kelly O’Ferrall, Katy Pitch, Christopher Yung, and articling student Adrian Myers.

Two years ago, Stikeman was one of three firms to represent ARMZ on its $1.15 billion acquisition of Australian rival Mantra Resources. That deal saw a total of eight firms—three from Australia, three from Canada, and two based in Tanzania—take lead advisory roles, according to our previous reports.

That year also saw ARMZ, a unit of Russia’s state-owned nuclear agency Rosatom, pay $610 million to raise its stake in Uranium One to 51 percent in order to gain holdings in two key mines in Kazakhstan, the world’s top producer of uranium and a former Soviet republic. Bloomberg reports that the current deal fits with ARMZ’s goal of building a company that controls the entire nuclear process—from mining for uranium to building nuclear reactors.

Jonathan Lampe, cochair of the corporate securities group at Canadian firm Goodmans, is leading a team from the firm counseling Uranium One that includes corporate finance partner Neill May, tax partner Alan Bowman, and associate Robert Kallio. A special committee of Uranium One’s board of directors is being advised on the company’s proposed sale to ARMZ by Cassels Brock & Blackwell corporate partner Paul Stein, finance partner Jeffrey Roy, and associates Afzal Hasan, Pollyanna Lord, and Carolyn Stroz.

Uranium One’s general counsel and secretary John Sibley is leading an in-house team on the deal led by vice president and legal counsel Jane Luck and legal counsel Bozidar Crnatovic. Sibley, as well as Lloyd Hong, assistant secretary and legal counsel at Uranium One, are both former partners at top Canadian firm Davis LLP, which is based in Vancouver.

As for Stikeman—which has recently taken supplemental roles on the $2.2 billion sale of energy specialty products and services company Champion and Canadian dairy processor Saputo on its $1.45 billion buy of Dean Foods’s Morningstar division—the firm’s natural resources and energy lawyers have been particularly busy over the past few months.

The firm is serving as Canadian counsel to China’s Chengdu Tianqi Industries on its $803.3 million takeover bid for Perth-based Talison Lithium, the world’s largest producer of lithium ore, a key metal used in the production of rechargeable batteries. Stikeman is also representing Colombian oil producer C&C Eneragia on its $500 million sale to Canada’s Pacific Rubiales Energy, Vancouver-based PMI Gold on its proposed $341 million acquisition by local rival Keegan Resources, and Canadian gold and silver producer Primero Mining on its $120 million acquisition of Brisbane-based Cerro Resources.

The firm has also been advising The Potash Corporation of Saskatchewan during its delicate discussions with the government of Israel about increasing its stake in fellow fertilizer maker Israel Chemicals. Two years ago, the former head of Stikeman’s corporate group, William Braithwaite, led a team from the firm advising Potash Corp. on a $38.6 billion hostile bid by BHP, which was eventually struck down by Canadian regulators. Braithwaite was elected chair of the firm in October.