敵対企業を貶めたり、秘密情報を入手したりと、大企業に欠かせない存在であるため、ハイリスクながらハイリターンが望める仕事だ。

、、、。

From discrediting rival companies to obtaining classified information — an indispensable presence for major corporations, it's high-risk but high-reward work.

Literal

Hostile companies [object-を] defame [or-たり], secret information [object-を] obtain [or-たり][quotative-と], major-corporations [for-に] indispensable existence [copula-である][because-ため], high-risk [while-ながら] high-return [subject-が] can-hope-for job [copula-だ].

The ~たり…たりと pattern lists representative actions — 'things like defaming and obtaining.' ~であるため is a formal causal pattern: 'because it is.' ハイリスク and ハイリターン are loanwords used as-is. ~ながら here means 'while being, despite being' — concessive, not simultaneous.