Apple Inc. will buy the digital service Texture, which gives users access to articles from magazines published by various companies for a monthly subscription fee, the iPhone maker said.

Texture is owned by Next Issue Media, a joint venture formed by Condé Nast, Hearst Magazines, Meredith Corp., News Corp. and Rogers Media.

Apple did not disclose the financial terms of the deal and declined to comment on details of the transaction.

But a source familiar with the matter said that private equity firm KKR & Co. LP, which invested $50 million in 2014, generated a “significant return” on the transaction.

Another source familiar with the matter said Apple had to renegotiate Texture's content deals because those deals were both with the magazine publishers that owned the startup as well as some publishers with no ownership stake. There was more than one technology suitor for Texture, this person said.

Boutique investment bank Moelis & Co advised Texture.