、○○。
According to informed sources, XYZ Corp is preparing to list on the First Section of the Tokyo Stock Exchange.
Literal
Informed-sources [according to-によると], XYZ company [topic-は] Tokyo-Stock-Exchange First Section [to-への] listing [object-を] is-preparing.
A standard news-business construction. ~によると ('according to X') is the evidential frame for citing a source; it pairs with a sentence ending in そうだ ('so I hear') or らしい in full form, though in news writing the hearsay marker is often dropped. 消息筋 ('informed sources,' literally 'sources close to the news') is the journalistic equivalent of 'sources close to the matter.' 東証一部 is the abbreviated form of 東京証券取引所一部 ('the First Section of the Tokyo Stock Exchange') — the top tier of Japanese-listed companies (the term and structure have since been restructured, but this sentence reflects the earlier naming). への is a composite particle: the directional へ + the genitive の, making a noun-modifying phrase 'toward X.'