CALGARY - Shares in Calfrac Well Services Ltd. rose on Friday after the company sweetened its recapitalization offer with cash for shareholders while it tries to fend off a rival American firm's takeover bid.

The Calgary-based oilfield services firm, which specializes in hydraulic fracturing or "fracking" of oil and gas wells, announced a revised plan under which each shareholder could elect to be paid 15 cents per share in cash, from a maximum pool of $10 million.

The shares rose by a cent to 15.5 cents in trading on the Toronto Stock Exchange. That matches the stock's highest closing price since Texas-based Wilks Brothers LLC launched a formal 18-cents-per-share takeover offer on Sept. 10.

"The new proposal is superior for equity holders than the prior Calfrac proposal, though the overall debt picture doesn't fundamentally change under the new proposal and the risk of covenant default continues to exist," said analyst Waqar Syed of ATB Capital Markets in a report.

The available cash, which would be borrowed, would cover about 46 per cent of the total common shares outstanding, he added.

The revised recapitalization plan includes the provision of two warrants per share with an exercise price of five cents for three years, potentially boosting the number of shares by 5.5 per cent, Syed pointed out.