Penn West has been selling assets to shore up its balance sheet, and the rules, Chief Executive Officer Dave Roberts says, will impact Penn West's activities.

"They have probably focused too much on some bad actors and I am not a big fan of lowest common denominator solutions," Roberts told reporters after Penn West's annual general meeting.

"Ultimately I think as they listen to their constituents, which are the 500 companies that are now frozen out of the asset transfer market, that they will come to a solution we can all live with."

The Alberta Energy Regulator (AER) announced a rule on Monday that companies seeking to buy oil and gas assets will need to show the deemed value of their production will exceed the deemed cost of cleaning up their inactive wells by a ratio of 2.0 or more after purchase, from 1.0 previously.

The AER made the change to stop weak companies from buying wells they may not be able to afford to decommission.

In a statement on Thursday, the AER said it "needed to ensure that Albertans were protected, that companies fulfill their obligations and that we prevent any opportunistic use of the decision to disclaim liabilities."

Around 200 companies are affected by the stricter rules, in addition to the 362 that did not qualify for asset purchases under the prior test.

Penn West announced in June it was selling its core Saskatchewan assets for C$975 million ($762.73 million) to Teine Energy. The company also plans to sell some of its energy assets in Alberta for about C$140 million.

Penn West warned in May it could default on its debt by the end of the second quarter due to the two-year oil slump.

Roberts told shareholders the company was now in a strong position to grow production by 10 percent annually, although output has been cut to 25,500 barrels of oil equivalent per day, down from 133,000 boepd in 2013.

He added the relationship between Penn West and its lenders was likely to improve. One Calgary-based source with direct knowledge of that relationship said it had soured over Penn West's previous reluctance to sell core assets.

(Reporting by Nia Williams; Editing by Diane Craft and Chris Reese)

By Nia Williams