The offer was previously set to expire at midnight on 28 September, but has been extended until midnight on 13 October.
HP is understood to have tabled an offer of $4.5bn for Mercury, which is involved in business technology optimisation (BTO) software and services.
BTO products help customers govern and manage IT, and optimise application quality, performance and availability.
HP is currently embroiled in a boardroom spying scandal over alleged illegal wiretapping that has already claimed a handful of the company's top brass.
After resigning Baskins declined to testify in front of the panel, citing her Fifth Amendment right not to give testimony that could be self-incriminating.
Although Dunn and Hurd expressed regrets in their testimonies, neither have admitted direct responsibility for the tactics that led to the HP investigation and congressional hearing.
Curiosity rover is in 'normal mode' but not transmitting scientific data back to base
NatWest outage comes a day after Barclays' IT systems shut out customers and staff
The ICO is concerned with AggregateIQ's retention and processing of data used in the Brexit referendum
Map selection, quick menus for grenades and healing items, and automatic reload all coming in PUBG update #22