The latest firm to step into shareholder litigation over Hewlett-Packard Co.’s disastrous acquisition of British software firm Autonomy Inc. is Skadden, Arps, Slate, Meagher & Flom.

Palo Alto partners Allen Ruby and Timothy Miller formally entered appearances Monday as counsel to a dozen members of HP’s board of directors, including Netscape co-founder Marc Andreessen; Booz & Co. CEO Shumeet Banerji; and McKesson Corp. CEO John Hammergren.

Skadden also represented the board in conducting due diligence prior to the $11 billion acquisition of Autonomy in 2011, a review which plaintiffs lawyers claim was inadequate. Investors also accuse the directors of hiding problems with the deal that subsequently came to light.

Last November, HP disclosed an $8.8 billion write-down related to the Autonomy purchase, spurring a wave of investor actions.

To date, roughly a dozen shareholder suits filed in the Northern District of California have been consolidated before U.S. District Judge Charles Breyer in San Francisco, yielding work for securities litigators across the country.

Last week, the newcomer was Williams & Connolly partner Steven Farina. Farina, a Washington, D.C., litigator, entered an appearance on behalf of accounting firm KPMG, which was engaged by HP to conduct accounting due diligence of Autonomy.

He previously represented New York Stock Exchange CEO Richard Grasso in litigation over his pay package.

Other firms now involved in the litigation include Morgan, Lewis & Bockius representing HP; Cooley for HP CEO Meg Whitman; Wilson Sonsini Goodrich & Rosati for HP CFO Catherine Lesjak; O’Melveny & Myers for former strategy and technology officer Shane Robison; and Fenwick & West for former controller James Murrin.

On the plaintiffs side, several law firms including Burlingame-based Cotchett, Pitre & McCarthy are vying for lead counsel appointments, with a hearing set for March 1.