Vista Outdoor received a new offer from MNC Capital to acquire the company and is delaying its scheduled shareholder vote on a competing offer from Czechoslovak Group (CSG), according to documents filed to the SEC.

MNC Capital submitted a revised offer last Friday of $43 per share in cash to buy the company outright, valuing the company at $2.51 billion. That’s a $1 per share increase from its previous offer in June.

But the offer expired Monday, causing frustration for Vista’s board of directors.

“The Vista Outdoor Board of Directors has been negotiating extensively with MNC,” read a Sept. 7 memo filed with the SEC. “Notwithstanding our good faith efforts, MNC sent the Board a revised proposal last evening after 10 pm ET that expires on Monday. The public communication by MNC only hours after delivery of the proposal as well as the Monday expiration continue a frustrating pattern and is not constructive.”

MNC acknowledged the Vista board’s “time, effort and responsiveness” in a letter to Vista on Sept. 9 and the parties are continuing to negotiate.

The previously scheduled shareholder vote on a counter-offer from CSG to acquire Vista’s ammunition arm of the company for $2.1 billion has now been delayed from Sept. 13 to Sept. 27.

Vista’s board previously recommended the CSG deal and rejected MNC’s offer, but several large shareholders indicated they would not vote in favor of the CSG offer and urged the board to negotiate with MNC.

Read our guide to Vista Outdoor’s long, tortured sale saga here.