The transaction, valued at $193.7 million, includes $36.6 million in debt.
Western is offering a combination of $1.24 in cash and 0.2338 of a Western share for each share of the Red Deer, Alta.-based well servicing and oilfield equipment rental company.
The combination, worth $3.10 per share, represents a 31 per cent premium to IROC's closing price of $2.37 on Thursday and a 32 per cent premium to its 20-day volume-weighted average of $2.35.
Vancouver-headquartered Western said the cash component of its offer is limited to just under $63 million and its stock component to a maximum of some $12.3 million shares.
Upon conclusion of the deal, Western shareholders would own about 83.8 per cent of the combined entity and IROC shareholders 16.2 per cent.
On the Toronto Stock Exchange, Western Energy shares were down 56 cents, or 7.07 per cent, at $7.36 in morning trading Friday, while IROC stock soared 60 cents, or more than 25 per cent, to $2.97.