Crystal Palace have formalised their interest in Christian Benteke by submitting an opening bid worth £25m to Liverpool for the Belgium forward.

The offer was tabled on the day Palace announced the signings of Andros Townsend, for what is currently a club record £13m from Newcastle United, and the France No2 goalkeeper, Steve Mandanda, for £1.4m from Marseille on a contract through to 2019. A fee of around £12m has also been agreed with West Ham United for the former England under-21s centre-half James Tomkins.

Interest in Benteke first surfaced in January as the Belgian laboured disappointingly through his first season at Anfield following a £32.5m move from Aston Villa last summer. Palace have now returned with a formal offer for the 25-year-old having lost out on the pursuit of his compatriot Michy Batshuayi, who has joined Chelsea from Marseille for £33.2m.

The initial bid for Benteke falls short of Liverpool’s £30m valuation of the forward, who scored 10 goals in 42 appearances last term, and will be rejected. Yet talks are expected to continue between the clubs to find a compromise and there is confidence at Palace that the player, who has also attracted interest from West Ham United, can be secured. Personal terms will not prove an issue for a striker seeking to revive his career.

Townsend, who has joined Palace’s ranks of wingers to supply Benteke, signed a five-year deal on Friday. “I’m extremely delighted,” said the 24-year-old, who was cut late from Roy Hodgson’s England squad for the European Championship. “I had chats with the manager and chairman [Steve Parish] before I signed and I’m pleased to be part of Crystal Palace’s future. By the sounds of things it’s going to be a bright one and I can’t wait to get started.”

Dwight Gayle has departed Palace for Newcastle in a separate deal worth an initial £8.5m.

The London club’s manager Alan Pardew, who has signed a new long-term contract at Selhurst Park, has been a long-standing admirer of Tomkins and has moved swiftly to add further defensive cover to his ranks. The 27-year-old is expected to sign over the next 48 hours, while interest is retained in Queens Park Rangers’ Steven Caulker and the young Wolves defender Dominic Iorfa.