TORONTO – Some of the most active companies traded Monday on the Toronto Stock Exchange and the TSX Venture Exchange:

Toronto Stock Exchange (13,472.22 down 6.12 points):

Detour Gold Corp. (TSX:DGC). Gold miner. Down 50 cents, or 11.71 per cent, at $3.77 on 9.09 million shares. The stock turned sharply lower after Detour announced that company founder and CEO Gerald Panneton had resigned, effective immediately. No reason was given.

Encana Corp. (TSX:ECA). Oil and gas. Down three cents, or 0.15 per cent, at $20.15 on 8.79 million shares. The energy sector dipped 0.91 per cent to 269.85 points as oil prices fell in the wake of a weekend agreement between Iran and world powers to curb Tehran’s nuclear program.

Yamana Gold Inc. (TSX:YRI). Miner. Up six cents, or 0.64 per cent, at $9.37 on 7.94 million shares.

B2Gold Corp. (TSX:BTO). Miner. Up two cents, or 0.93 per cent, at $2.17 on 5.39 million shares.

Revolution Resources Corp. (TSXS:RV). Miner. Down half a cent, or 25 per cent, at 1.5 cents on 4.32 million shares.

Toronto Venture Exchange (929.26 down 2.89 points):

Africa Hydrocarbons Inc. (TSXV:NFK). Oil and gas. Up five cents, or 55.56 per cent, at 14 cents on 9.26 million shares. The Calgary-based company said that operations at its well in Tunisia are ongoing despite earlier setbacks related to its acid injection program.

Colombia Crest Gold Corp. (TSXV:CLB). Unchanged at half a cent, on 4.10 million shares.

Companies reporting major news:

BlackBerry Ltd. (TSX:BB). Wireless technology. Up nine cents, or 1.38 per cent, at $6.60 on 842,639 shares. The smartphone maker will leave two executive positions unfilled as chief operating officer Kristian Tear and chief marketing officer Frank Boulben depart. Both joined the smartphone maker in mid-2012 in the buildup to the release of the new BlackBerry smartphones, which have seen sales fizzle.

Saputo (TSX:SAP). Dairy processor. Up six cents, or 0.12 per cent, at $48.60 on 186,345 shares. The company sweetened its bid for Australia’s oldest dairy processor, offering AUD$9.20 per share if it acquires a majority of Warrnambool Cheese and Butter shares. The new bid added 20 cents per share to its earlier unconditional offer and tops two rival Australian bidders.