Arsenal have confirmed the sale of Danish striker Mika Biereth to Austrian outfit Sturm Graz, ending his three-year spell in North London.

The 21-year-old joined the Gunners' Hale End academy ranks from Fulham in the summer of 2021, on the back of registering 21 goals and 13 assists in 21 Under-18 Premier League matches in the 2020-21 season.

Biereth quickly hit the ground running in North London too, scoring 11 goals and setting up four more in 21 matches for the Under-21s in the 2021-22 Premier League 2 season, as well as being invited to train with the first team.

The Denmark youth international made the bench for the Gunners in the Premier League, EFL Cup and FA Cup that year, but he failed to make his senior debut for Mikel Arteta's side and endured a difficult loan spell with RKC Waalwijk in the 2022-23 campaign.

However, Biereth shone with with Motherwell and Sturm Graz in the 2023-24 campaign, contributing to 11 goals in 15 games for the former before moving to Austria for the second half of the season.

Arsenal "so proud" of Biereth as exit confirmed

While there, Biereth came up with nine goals and four assists in 22 matches for Sturm Graz, helping his new club dethrone Red Bull Salzburg and complete an Austrian Bundesliga and Cup double.

Despite his rise to prominence, Biereth will not be given the chance to prove himself in the Arsenal first team and has now signed for Sturm Graz for a reported fee of £4m, making him the Austrian champions' most expensive signing of all time.

Arsenal sporting director Edu talked up the 21-year-old's progress in North London as his exit was confirmed, telling the Gunners website: "We are so proud of the progress Mika has made since joining us.

"This new opportunity with Sturm Graz is great for Mika, and it's a good example of what a strong loan development plan produces. Mika will be playing Champions League football when the season starts again, which he deserves due to his mentality and performances in recent seasons."

Speaking to the Sturm Graz website after signing his four-year contract, Biereth said that he was "really happy" to be back in Austria and looked ahead to competing in the Champions League with the Austrian Bundesliga holders.

Sturm Graz director lifts lid on Arsenal transfer talks

"I think everyone has seen how comfortable I felt here at the club and in the team during my loan. Added to that was the great sporting success with the double and qualification for the Champions League, which I am extremely excited about," Biereth said.

"I would like to thank Andreas Schicker for trying so hard for me and I am extremely excited to hopefully repay his trust and achieve our goals together with the team. Let's go Schwoaze, I am really happy to be back in Graz!"

Sturm Graz managing director Thomas Tebbich admitted that talks with the Gunners were "tough" but "fair" as his side took a "big step economically" to wrap up the Biereth deal, adding: "We are extremely happy that Mika is now a player for SK Sturm after tough but fair and appreciative negotiations.

"It is of course clear that we had to take a big step economically for this transfer, but we are absolutely convinced of Mika and his potential and are therefore sure that this transfer will bring us a lot of joy!"

Biereth's transfer to Sturm Graz comes just one day after another ex-Arsenal academy product Amario Cozier-Duberry joined Brighton & Hove Albion, while talented defender Reuell Walters is on the hunt for a new club after rejecting the chance to stay at the Emirates.